Provided by: pgloader_3.4.1+dfsg-1_amd64 
NAME
pgloader - PostgreSQL data loader
SYNOPSIS
pgloader [<options>] [<command-file>]...
pgloader [<options>] SOURCE TARGET
DESCRIPTION
pgloader loads data from various sources into PostgreSQL. It can transform the data it reads on the fly
and submit raw SQL before and after the loading. It uses the COPY PostgreSQL protocol to stream the data
into the server, and manages errors by filling a pair of reject.dat and reject.log files.
pgloader operates either using commands which are read from files:
pgloader commands.load
or by using arguments and options all provided on the command line:
pgloader SOURCE TARGET
ARGUMENTS
The pgloader arguments can be as many load files as needed, or a couple of connection strings to a
specific input file.
SOURCE CONNECTION STRING
The source connection string format is as follows:
format:///absolute/path/to/file.ext
format://./relative/path/to/file.ext
Where format might be one of csv, fixed, copy, dbf, db3 or ixf.
db://user:pass@host:port/dbname
Where db might be of sqlite, mysql or mssql.
When using a file based source format, pgloader also support natively fetching the file from an http
location and decompressing an archive if needed. In that case it´s necessary to use the --type option to
specify the expected format of the file. See the examples below.
Also note that some file formats require describing some implementation details such as columns to be
read and delimiters and quoting when loading from csv.
For more complex loading scenarios, you will need to write a full fledge load command in the syntax
described later in this document.
TARGET CONNECTION STRING
The target connection string format is described in details later in this document, see Section
Connection String.
OPTIONS
INQUIRY OPTIONS
Use these options when you want to know more about how to use pgloader, as those options will cause
pgloader not to load any data.
-h, --help
Show command usage summary and exit.
-V, --version
Show pgloader version string and exit.
-E, --list-encodings
List known encodings in this version of pgloader.
-U, --upgrade-config
Parse given files in the command line as pgloader.conf files with the INI syntax that was in use
in pgloader versions 2.x, and output the new command syntax for pgloader on standard output.
GENERAL OPTIONS
Those options are meant to tweak pgloader behavior when loading data.
• -v, --verbose: Be verbose.
• -q, --quiet: Be quiet.
• -d, --debug: Show debug level information messages.
• -D, --root-dir: Set the root working directory (default to "/tmp/pgloader").
• -L, --logfile: Set the pgloader log file (default to "/tmp/pgloader.log").
• --log-min-messages: Minimum level of verbosity needed for log message to make it to the logfile. One
of critical, log, error, warning, notice, info or debug.
• --client-min-messages: Minimum level of verbosity needed for log message to make it to the console.
One of critical, log, error, warning, notice, info or debug.
• -S, --summary: A filename where to copy the summary output. When relative, the filename is expanded
into *root-dir*.
The format of the filename defaults to being human readable. It is possible to have the output in
machine friendly formats such as CSV, COPY (PostgreSQL´s own COPY format) or JSON by specifying a
filename with the extension resp. .csv, .copy or .json.
• -l <file>, --load-lisp-file <file>: Specify a lisp file to compile and load into the pgloader image
before reading the commands, allowing to define extra transformation function. Those functions should
be defined in the pgloader.transforms package. This option can appear more than once in the command
line.
• --dry-run:
Allow testing a .load file without actually trying to load any data. It´s useful to debug it until
it´s ok, in particular to fix connection strings.
• --on-error-stop
Alter pgloader behavior: rather than trying to be smart about error handling and continue loading
good data, separating away the bad one, just stop as soon as PostgreSQL refuses anything sent to it.
Useful to debug data processing, transformation function and specific type casting.
• --self-upgrade <directory>:
Specify a directory where to find pgloader sources so that one of the very first things it does is
dynamically loading-in (and compiling to machine code) another version of itself, usually a newer one
like a very recent git checkout.
COMMAND LINE ONLY OPERATIONS
Those options are meant to be used when using pgloader from the command line only, rather than using a
command file and the rich command clauses and parser. In simple cases, it can be much easier to use the
SOURCE and TARGET directly on the command line, then tweak the loading with those options:
• --with "option":
Allows setting options from the command line. You can use that option as many times as you want. The
option arguments must follow the WITH clause for the source type of the SOURCE specification, as
described later in this document.
• --set "guc_name=´value´"
Allows setting PostgreSQL configuration from the command line. Note that the option parsing is the
same as when used from the SET command clause, in particular you must enclose the guc value with
single-quotes.
• --field "..."
Allows setting a source field definition. Fields are accumulated in the order given on the command
line. It´s possible to either use a --field option per field in the source file, or to separate field
definitions by a comma, as you would do in the HAVING FIELDS clause.
• --cast "..."
Allows setting a specific casting rule for loading the data.
• --type csv|fixed|db3|ixf|sqlite|mysql|mssql
Allows forcing the source type, in case when the SOURCE parsing isn´t satisfying.
• --encoding <encoding>
Set the encoding of the source file to load data from.
• --before <filename>
Parse given filename for SQL queries and run them against the target database before loading the data
from the source. The queries are parsed by pgloader itself: they need to be terminated by a
semi-colon (;) and the file may include \i or \ir commands to include another file.
• --after <filename>
Parse given filename for SQL queries and run them against the target database after having loaded the
data from the source. The queries are parsed in the same way as with the --before option, see above.
MORE DEBUG INFORMATION
To get the maximum amount of debug information, you can use both the --verbose and the --debug switches
at the same time, which is equivalent to saying --client-min-messages data. Then the log messages will
show the data being processed, in the cases where the code has explicit support for it.
USAGE EXAMPLES
Review the command line options and pgloader´s version:
pgloader --help
pgloader --version
Loading from a complex command
Use the command file as the pgloader command argument, pgloader will parse that file and execute the
commands found in it:
pgloader --verbose ./test/csv-districts.load
CSV
Load data from a CSV file into a pre-existing table in your database:
pgloader --type csv \
--field id --field field \
--with truncate \
--with "fields terminated by ´,´" \
./test/data/matching-1.csv \
postgres:///pgloader?tablename=matching
In that example the whole loading is driven from the command line, bypassing the need for writing a
command in the pgloader command syntax entirely. As there´s no command though, the extra inforamtion
needed must be provided on the command line using the --type and --field and --with switches.
For documentation about the available syntaxes for the --field and --with switches, please refer to the
CSV section later in the man page.
Note also that the PostgreSQL URI includes the target tablename.
Reading from STDIN
File based pgloader sources can be loaded from the standard input, as in the following example:
pgloader --type csv \
--field "usps,geoid,aland,awater,aland_sqmi,awater_sqmi,intptlat,intptlong" \
--with "skip header = 1" \
--with "fields terminated by ´\t´" \
- \
postgresql:///pgloader?districts_longlat \
< test/data/2013_Gaz_113CDs_national.txt
The dash (-) character as a source is used to mean standard input, as usual in Unix command lines. It´s
possible to stream compressed content to pgloader with this technique, using the Unix pipe:
gunzip -c source.gz | pgloader --type csv ... - pgsql:///target?foo
Loading from CSV available through HTTP
The same command as just above can also be run if the CSV file happens to be found on a remote HTTP
location:
pgloader --type csv \
--field "usps,geoid,aland,awater,aland_sqmi,awater_sqmi,intptlat,intptlong" \
--with "skip header = 1" \
--with "fields terminated by ´\t´" \
http://pgsql.tapoueh.org/temp/2013_Gaz_113CDs_national.txt \
postgresql:///pgloader?districts_longlat
Some more options have to be used in that case, as the file contains a one-line header (most commonly
that´s column names, could be a copyright notice). Also, in that case, we specify all the fields right
into a single --field option argument.
Again, the PostgreSQL target connection string must contain the tablename option and you have to ensure
that the target table exists and may fit the data. Here´s the SQL command used in that example in case
you want to try it yourself:
create table districts_longlat
(
usps text,
geoid text,
aland bigint,
awater bigint,
aland_sqmi double precision,
awater_sqmi double precision,
intptlat double precision,
intptlong double precision
);
Also notice that the same command will work against an archived version of the same data, e.g.
http://pgsql.tapoueh.org/temp/2013_Gaz_113CDs_national.txt.gz.
Finally, it´s important to note that pgloader first fetches the content from the HTTP URL it to a local
file, then expand the archive when it´s recognized to be one, and only then processes the locally
expanded file.
In some cases, either because pgloader has no direct support for your archive format or maybe because
expanding the archive is not feasible in your environment, you might want to stream the content straight
from its remote location into PostgreSQL. Here´s how to do that, using the old battle tested Unix Pipes
trick:
curl http://pgsql.tapoueh.org/temp/2013_Gaz_113CDs_national.txt.gz \
| gunzip -c \
| pgloader --type csv \
--field "usps,geoid,aland,awater,aland_sqmi,awater_sqmi,intptlat,intptlong"
--with "skip header = 1" \
--with "fields terminated by ´\t´" \
- \
postgresql:///pgloader?districts_longlat
Now the OS will take care of the streaming and buffering between the network and the commands and
pgloader will take care of streaming the data down to PostgreSQL.
Migrating from SQLite
The following command will open the SQLite database, discover its tables definitions including indexes
and foreign keys, migrate those definitions while casting the data type specifications to their
PostgreSQL equivalent and then migrate the data over:
createdb newdb
pgloader ./test/sqlite/sqlite.db postgresql:///newdb
Migrating from MySQL
Just create a database where to host the MySQL data and definitions and have pgloader do the migration
for you in a single command line:
createdb pagila
pgloader mysql://user@localhost/sakila postgresql:///pagila
Fetching an archived DBF file from a HTTP remote location
It´s possible for pgloader to download a file from HTTP, unarchive it, and only then open it to discover
the schema then load the data:
createdb foo
pgloader --type dbf http://www.insee.fr/fr/methodes/nomenclatures/cog/telechargement/2013/dbf/historiq2013.zip postgresql:///foo
Here it´s not possible for pgloader to guess the kind of data source it´s being given, so it´s necessary
to use the --type command line switch.
BATCHES AND RETRY BEHAVIOUR
To load data to PostgreSQL, pgloader uses the COPY streaming protocol. While this is the faster way to
load data, COPY has an important drawback: as soon as PostgreSQL emits an error with any bit of data sent
to it, whatever the problem is, the whole data set is rejected by PostgreSQL.
To work around that, pgloader cuts the data into batches of 25000 rows each, so that when a problem
occurs it´s only impacting that many rows of data. Each batch is kept in memory while the COPY streaming
happens, in order to be able to handle errors should some happen.
When PostgreSQL rejects the whole batch, pgloader logs the error message then isolates the bad row(s)
from the accepted ones by retrying the batched rows in smaller batches. To do that, pgloader parses the
CONTEXT error message from the failed COPY, as the message contains the line number where the error was
found in the batch, as in the following example:
CONTEXT: COPY errors, line 3, column b: "2006-13-11"
Using that information, pgloader will reload all rows in the batch before the erroneous one, log the
erroneous one as rejected, then try loading the remaining of the batch in a single attempt, which may or
may not contain other erroneous data.
At the end of a load containing rejected rows, you will find two files in the root-dir location, under a
directory named the same as the target database of your setup. The filenames are the target table, and
their extensions are .dat for the rejected data and .log for the file containing the full PostgreSQL
client side logs about the rejected data.
The .dat file is formatted in PostgreSQL the text COPY format as documented in
http://www.postgresql.org/docs/9.2/static/sql-copy.html#AEN66609 .
A NOTE ABOUT PERFORMANCE
pgloader has been developed with performance in mind, to be able to cope with ever growing needs in
loading large amounts of data into PostgreSQL.
The basic architecture it uses is the old Unix pipe model, where a thread is responsible for loading the
data (reading a CSV file, querying MySQL, etc) and fills pre-processed data into a queue. Another threads
feeds from the queue, apply some more transformations to the input data and stream the end result to
PostgreSQL using the COPY protocol.
When given a file that the PostgreSQL COPY command knows how to parse, and if the file contains no
erroneous data, then pgloader will never be as fast as just using the PostgreSQL COPY command.
Note that while the COPY command is restricted to read either from its standard input or from a local
file on the server´s file system, the command line tool psql implements a \copy command that knows how to
stream a file local to the client over the network and into the PostgreSQL server, using the same
protocol as pgloader uses.
A NOTE ABOUT PARALLELISM
pgloader uses several concurrent tasks to process the data being loaded:
• a reader task reads the data in and pushes it to a queue,
• at last one write task feeds from the queue and formats the raw into the PostgreSQL COPY format in
batches (so that it´s possible to then retry a failed batch without reading the data from source
again), and then sends the data to PostgreSQL using the COPY protocol.
The parameter workers allows to control how many worker threads are allowed to be active at any time
(that´s the parallelism level); and the parameter concurrency allows to control how many tasks are
started to handle the data (they may not all run at the same time, depending on the workers setting).
We allow workers simultaneous workers to be active at the same time in the context of a single table. A
single unit of work consist of several kinds of workers:
• a reader getting raw data from the source,
• N writers preparing and sending the data down to PostgreSQL.
The N here is setup to the concurrency parameter: with a CONCURRENCY of 2, we start (+ 1 2) = 3
concurrent tasks, with a concurrency of 4 we start (+ 1 4) = 9 concurrent tasks, of which only workers
may be active simultaneously.
The defaults are workers = 4, concurrency = 1 when loading from a database source, and workers = 8,
concurrency = 2 when loading from something else (currently, a file). Those defaults are arbitrary and
waiting for feedback from users, so please consider providing feedback if you play with the settings.
As the CREATE INDEX threads started by pgloader are only waiting until PostgreSQL is done with the real
work, those threads are NOT counted into the concurrency levels as detailed here.
By default, as many CREATE INDEX threads as the maximum number of indexes per table are found in your
source schema. It is possible to set the max parallel create index WITH option to another number in case
there´s just too many of them to create.
SOURCE FORMATS
pgloader supports the following input formats:
• csv, which includes also tsv and other common variants where you can change the separator and the
quoting rules and how to escape the quotes themselves;
• fixed columns file, where pgloader is flexible enough to accomodate with source files missing columns
(ragged fixed length column files do exist);
• PostgreSLQ COPY formatted files, following the COPY TEXT documentation of PostgreSQL, such as the
reject files prepared by pgloader;
• dbase files known as db3 or dbf file;
• ixf formated files, ixf being a binary storage format from IBM;
• sqlite databases with fully automated discovery of the schema and advanced cast rules;
• mysql databases with fully automated discovery of the schema and advanced cast rules;
• MS SQL databases with fully automated discovery of the schema and advanced cast rules.
PGLOADER COMMANDS SYNTAX
pgloader implements a Domain Specific Language allowing to setup complex data loading scripts handling
computed columns and on-the-fly sanitization of the input data. For more complex data loading scenarios,
you will be required to learn that DSL´s syntax. It´s meant to look familiar to DBA by being inspired by
SQL where it makes sense, which is not that much after all.
The pgloader commands follow the same global grammar rules. Each of them might support only a subset of
the general options and provide specific options.
LOAD <source-type>
FROM <source-url> [ HAVING FIELDS <source-level-options> ]
INTO <postgresql-url> [ TARGET COLUMNS <columns-and-options> ]
[ WITH <load-options> ]
[ SET <postgresql-settings> ]
[ BEFORE LOAD [ DO <sql statements> | EXECUTE <sql file> ] ... ]
[ AFTER LOAD [ DO <sql statements> | EXECUTE <sql file> ] ... ]
;
The main clauses are the LOAD, FROM, INTO and WITH clauses that each command implements. Some command
then implement the SET command, or some specific clauses such as the CAST clause.
COMMON CLAUSES
Some clauses are common to all commands:
• FROM
The FROM clause specifies where to read the data from, and each command introduces its own variant of
sources. For instance, the CSV source supports inline, stdin, a filename, a quoted filename, and a
FILENAME MATCHING clause (see above); whereas the MySQL source only supports a MySQL database URI
specification.
In all cases, the FROM clause is able to read its value from an environment variable when using the
form GETENV ´varname´.
• INTO
The PostgreSQL connection URI must contains the name of the target table where to load the data into.
That table must have already been created in PostgreSQL, and the name might be schema qualified.
The INTO target database connection URI can be parsed from the value of an environment variable when
using the form GETENV ´varname´.
Then INTO option also supports an optional comma separated list of target columns, which are either
the name of an input field or the white space separated list of the target column name, its
PostgreSQL data type and a USING expression.
The USING expression can be any valid Common Lisp form and will be read with the current package set
to pgloader.transforms, so that you can use functions defined in that package, such as functions
loaded dynamically with the --load command line parameter.
Each USING expression is compiled at runtime to native code.
This feature allows pgloader to load any number of fields in a CSV file into a possibly different
number of columns in the database, using custom code for that projection.
• WITH
Set of options to apply to the command, using a global syntax of either:
• key = value
• use option
• do not use option
See each specific command for details.
All data sources specific commands support the following options:
• on error stop
• batch rows = R
• batch size = ... MB
• prefetch rows = ...
See the section BATCH BEHAVIOUR OPTIONS for more details.
In addition, the following settings are available:
• workers = W
• concurrency = C
• max parallel create index = I
See section A NOTE ABOUT PARALLELISM for more details.
• SET
This clause allows to specify session parameters to be set for all the sessions opened by pgloader.
It expects a list of parameter name, the equal sign, then the single-quoted value as a comma
separated list.
The names and values of the parameters are not validated by pgloader, they are given as-is to
PostgreSQL.
• BEFORE LOAD DO
You can run SQL queries against the database before loading the data from the CSV file. Most common
SQL queries are CREATE TABLE IF NOT EXISTS so that the data can be loaded.
Each command must be dollar-quoted: it must begin and end with a double dollar sign, $$.
Dollar-quoted queries are then comma separated. No extra punctuation is expected after the last SQL
query.
• BEFORE LOAD EXECUTE
Same behaviour as in the BEFORE LOAD DO clause. Allows you to read the SQL queries from a SQL file.
Implements support for PostgreSQL dollar-quoting and the \i and \ir include facilities as in psql
batch mode (where they are the same thing).
• AFTER LOAD DO
Same format as BEFORE LOAD DO, the dollar-quoted queries found in that section are executed once the
load is done. That´s the right time to create indexes and constraints, or re-enable triggers.
• AFTER LOAD EXECUTE
Same behaviour as in the AFTER LOAD DO clause. Allows you to read the SQL queries from a SQL file.
Implements support for PostgreSQL dollar-quoting and the \i and \ir include facilities as in psql
batch mode (where they are the same thing).
Connection String
The <postgresql-url> parameter is expected to be given as a Connection URI as documented in the
PostgreSQL documentation at
http://www.postgresql.org/docs/9.3/static/libpq-connect.html#LIBPQ-CONNSTRING.
postgresql://[user[:password]@][netloc][:port][/dbname][?option=value&...]
Where:
• user
Can contain any character, including colon (:) which must then be doubled (::) and at-sign (@) which
must then be doubled (@@).
When omitted, the user name defaults to the value of the PGUSER environment variable, and if it is
unset, the value of the USER environment variable.
• password
Can contain any character, including the at sign (@) which must then be doubled (@@). To leave the
password empty, when the user name ends with at at sign, you then have to use the syntax user:@.
When omitted, the password defaults to the value of the PGPASSWORD environment variable if it is set,
otherwise the password is left unset.
• netloc
Can be either a hostname in dotted notation, or an ipv4, or an Unix domain socket path. Empty is the
default network location, under a system providing unix domain socket that method is preferred,
otherwise the netloc default to localhost.
It´s possible to force the unix domain socket path by using the syntax
unix:/path/to/where/the/socket/file/is, so to force a non default socket path and a non default port,
you would have:
postgresql://unix:/tmp:54321/dbname
The netloc defaults to the value of the PGHOST environment variable, and if it is unset, to either the
default unix socket path when running on a Unix system, and localhost otherwise.
• dbname
Should be a proper identifier (letter followed by a mix of letters, digits and the punctuation signs
comma (,), dash (-) and underscore (_).
When omitted, the dbname defaults to the value of the environment variable PGDATABASE, and if that is
unset, to the user value as determined above.
• options
The optional parameters must be supplied with the form name=value, and you may use several parameters
by separating them away using an ampersand (&) character.
Only some options are supported here, tablename (which might be qualified with a schema name)
sslmode, host, port, dbname, user and password.
The sslmode parameter values can be one of disable, allow, prefer or require.
For backward compatibility reasons, it´s possible to specify the tablename option directly, without
spelling out the tablename= parts.
The options override the main URI components when both are given, and using the percent-encoded
option parameters allow using passwords starting with a colon and bypassing other URI components
parsing limitations.
Regular Expressions
Several clauses listed in the following accept regular expressions with the following input rules:
• A regular expression begins with a tilde sign (~),
• is then followed with an opening sign,
• then any character is allowed and considered part of the regular expression, except for the closing
sign,
• then a closing sign is expected.
The opening and closing sign are allowed by pair, here´s the complete list of allowed delimiters:
~//
~[]
~{}
~()
~<>
~""
~´´
~||
~##
Pick the set of delimiters that don´t collide with the regular expression you´re trying to input. If your
expression is such that none of the solutions allow you to enter it, the places where such expressions
are allowed should allow for a list of expressions.
Comments
Any command may contain comments, following those input rules:
• the -- delimiter begins a comment that ends with the end of the current line,
• the delimiters /* and */ respectively start and end a comment, which can be found in the middle of a
command or span several lines.
Any place where you could enter a whitespace will accept a comment too.
Batch behaviour options
All pgloader commands have support for a WITH clause that allows for specifying options. Some options are
generic and accepted by all commands, such as the batch behaviour options, and some options are specific
to a data source kind, such as the CSV skip header option.
The global batch behaviour options are:
• batch rows
Takes a numeric value as argument, used as the maximum number of rows allowed in a batch. The default
is 25 000 and can be changed to try having better performance characteristics or to control pgloader
memory usage;
• batch size
Takes a memory unit as argument, such as 20 MB, its default value. Accepted multipliers are kB, MB,
GB, TB and PB. The case is important so as not to be confused about bits versus bytes, we´re only
talking bytes here.
• prefetch rows
Takes a numeric value as argument, defaults to 100000. That´s the number of rows that pgloader is
allowed to read in memory in each reader thread. See the workers setting for how many reader threads
are allowed to run at the same time.
Other options are specific to each input source, please refer to specific parts of the documentation for
their listing and covering.
A batch is then closed as soon as either the batch rows or the batch size threshold is crossed, whichever
comes first. In cases when a batch has to be closed because of the batch size setting, a debug level log
message is printed with how many rows did fit in the oversized batch.
LOAD CSV
This command instructs pgloader to load data from a CSV file. Here´s an example:
LOAD CSV
FROM ´GeoLiteCity-Blocks.csv´ WITH ENCODING iso-646-us
HAVING FIELDS
(
startIpNum, endIpNum, locId
)
INTO postgresql://user@localhost:54393/dbname?geolite.blocks
TARGET COLUMNS
(
iprange ip4r using (ip-range startIpNum endIpNum),
locId
)
WITH truncate,
skip header = 2,
fields optionally enclosed by ´"´,
fields escaped by backslash-quote,
fields terminated by ´\t´
SET work_mem to ´32 MB´, maintenance_work_mem to ´64 MB´;
The csv format command accepts the following clauses and options:
• FROM
Filename where to load the data from. Accepts an ENCODING option. Use the --list-encodings option to
know which encoding names are supported.
The filename may be enclosed by single quotes, and could be one of the following special values:
• inline
The data is found after the end of the parsed commands. Any number of empty lines between the end of
the commands and the beginning of the data is accepted.
• stdin
Reads the data from the standard input stream.
• FILENAMES MATCHING
The whole matching clause must follow the following rule:
[ ALL FILENAMES | [ FIRST ] FILENAME ]
MATCHING regexp
[ IN DIRECTORY ´...´ ]
The matching clause applies given regular expression (see above for exact syntax, several options can be
used here) to filenames. It´s then possible to load data from only the first match of all of them.
The optional IN DIRECTORY clause allows specifying which directory to walk for finding the data files,
and can be either relative to where the command file is read from, or absolute. The given directory must
exists.
The FROM option also supports an optional comma separated list of field names describing what is expected
in the CSV data file, optionally introduced by the clause HAVING FIELDS.
Each field name can be either only one name or a name following with specific reader options for that
field, enclosed in square brackets and comma-separated. Supported per-field reader options are:
• terminated by
See the description of field terminated by below.
The processing of this option is not currently implemented.
• date format
When the field is expected of the date type, then this option allows to specify the date format used
in the file.
Date format string are template strings modeled against the PostgreSQL to_char template strings
support, limited to the following patterns:
• YYYY, YYY, YY for the year part
• MM for the numeric month part
• DD for the numeric day part
• HH, HH12, HH24 for the hour part
• am, AM, a.m., A.M.
• pm, PM, p.m., P.M.
• MI for the minutes part
• SS for the seconds part
• MS for the milliseconds part (4 digits)
• US for the microseconds part (6 digits)
• unparsed punctuation signs: - . * # @ T / \ and space
Here´s an example of a date format specification:
column-name [date format ´YYYY-MM-DD HH24-MI-SS.US´]
• null if
This option takes an argument which is either the keyword blanks or a double-quoted string.
When blanks is used and the field value that is read contains only space characters, then it´s
automatically converted to an SQL NULL value.
When a double-quoted string is used and that string is read as the field value, then the field value
is automatically converted to an SQL NULL value.
• trim both whitespace, trim left whitespace, trim right whitespace
This option allows to trim whitespaces in the read data, either from both sides of the data, or only
the whitespace characters found on the left of the streaing, or only those on the right of the
string.
• WITH
When loading from a CSV file, the following options are supported:
• truncate
When this option is listed, pgloader issues a TRUNCATE command against the PostgreSQL target table
before reading the data file.
• drop indexes
When this option is listed, pgloader issues DROP INDEX commands against all the indexes defined on
the target table before copying the data, then CREATE INDEX commands once the COPY is done.
In order to get the best performance possible, all the indexes are created in parallel and when done
the primary keys are built again from the unique indexes just created. This two step process allows
creating the primary key index in parallel with the other indexes, as only the ALTER TABLE command
needs an access exclusive lock on the target table.
• disable triggers
When this option is listed, pgloader issues an ALTER TABLE ... DISABLE TRIGGER ALL command against
the PostgreSQL target table before copying the data, then the command ALTER TABLE ... ENABLE TRIGGER
ALL once the COPY is done.
This option allows loading data into a pre-existing table ignoring the foreign key constraints and
user defined triggers and may result in invalid foreign key constraints once the data is loaded. Use
with care.
• skip header
Takes a numeric value as argument. Instruct pgloader to skip that many lines at the beginning of the
input file.
• csv header
Use the first line read after skip header as the list of csv field names to be found in the CSV file,
using the same CSV parameters as for the CSV data.
• trim unquoted blanks
When reading unquoted values in the CSV file, remove the blanks found in between the separator and
the value. That behaviour is the default.
• keep unquoted blanks
When reading unquoted values in the CSV file, keep blanks found in between the separator and the
value.
• fields optionally enclosed by
Takes a single character as argument, which must be found inside single quotes, and might be given as
the printable character itself, the special value \t to denote a tabulation character, or 0x then an
hexadecimal value read as the ASCII code for the character.
This character is used as the quoting character in the CSV file, and defaults to double-quote.
• fields not enclosed
By default, pgloader will use the double-quote character as the enclosing character. If you have a
CSV file where fields are not enclosed and are using double-quote as an expected ordinary character,
then use the option fields not enclosed for the CSV parser to accept those values.
• fields escaped by
Takes either the special value backslash-quote or double-quote, or any value supported by the fields
terminated by option (see below). This value is used to recognize escaped field separators when they
are to be found within the data fields themselves. Defaults to double-quote.
• csv escape mode
Takes either the special value quote (the default) or following and allows the CSV parser to parse
either only escaped field separator or any character (including CSV data) when using the following
value.
• fields terminated by
Takes a single character as argument, which must be found inside single quotes, and might be given as
the printable character itself, the special value \t to denote a tabulation character, or 0x then an
hexadecimal value read as the ASCII code for the character.
This character is used as the field separator when reading the CSV data.
• lines terminated by
Takes a single character as argument, which must be found inside single quotes, and might be given as
the printable character itself, the special value \t to denote a tabulation character, or 0x then an
hexadecimal value read as the ASCII code for the character.
This character is used to recognize end-of-line condition when reading the CSV data.
LOAD FIXED COLS
This command instructs pgloader to load data from a text file containing columns arranged in a fixed size
manner. Here´s an example:
LOAD FIXED
FROM inline
(
a from 0 for 10,
b from 10 for 8,
c from 18 for 8,
d from 26 for 17 [null if blanks, trim right whitespace]
)
INTO postgresql:///pgloader?fixed
(
a, b,
c time using (time-with-no-separator c),
d
)
WITH truncate
SET work_mem to ´14MB´,
standard_conforming_strings to ´on´
BEFORE LOAD DO
$$ drop table if exists fixed; $$,
$$ create table fixed (
a integer,
b date,
c time,
d text
);
$$;
01234567892008052011431250firstline
01234562008052115182300left blank-padded
12345678902008052208231560another line
2345609872014092914371500
2345678902014092914371520
The fixed format command accepts the following clauses and options:
• FROM
Filename where to load the data from. Accepts an ENCODING option. Use the --list-encodings option to
know which encoding names are supported.
The filename may be enclosed by single quotes, and could be one of the following special values:
• inline
The data is found after the end of the parsed commands. Any number of empty lines between the end of
the commands and the beginning of the data is accepted.
• stdin
Reads the data from the standard input stream.
• FILENAMES MATCHING
The whole matching clause must follow the following rule:
[ ALL FILENAMES | [ FIRST ] FILENAME ]
MATCHING regexp
[ IN DIRECTORY ´...´ ]
The matching clause applies given regular expression (see above for exact syntax, several options can be
used here) to filenames. It´s then possible to load data from only the first match of all of them.
The optional IN DIRECTORY clause allows specifying which directory to walk for finding the data files,
and can be either relative to where the command file is read from, or absolute. The given directory must
exists.
The FROM option also supports an optional comma separated list of field names describing what is expected
in the FIXED data file.
Each field name is composed of the field name followed with specific reader options for that field.
Supported per-field reader options are the following, where only start and length are required.
• start
Position in the line where to start reading that field´s value. Can be entered with decimal digits or
0x then hexadecimal digits.
• length
How many bytes to read from the start position to read that field´s value. Same format as start.
Those optional parameters must be enclosed in square brackets and comma-separated:
• terminated by
See the description of field terminated by below.
The processing of this option is not currently implemented.
• date format
When the field is expected of the date type, then this option allows to specify the date format used
in the file.
Date format string are template strings modeled against the PostgreSQL to_char template strings
support, limited to the following patterns:
• YYYY, YYY, YY for the year part
• MM for the numeric month part
• DD for the numeric day part
• HH, HH12, HH24 for the hour part
• am, AM, a.m., A.M.
• pm, PM, p.m., P.M.
• MI for the minutes part
• SS for the seconds part
• MS for the milliseconds part (4 digits)
• US for the microseconds part (6 digits)
• unparsed punctuation signs: - . * # @ T / \ and space
Here´s an example of a date format specification:
column-name [date format ´YYYY-MM-DD HH24-MI-SS.US´]
• null if
This option takes an argument which is either the keyword blanks or a double-quoted string.
When blanks is used and the field value that is read contains only space characters, then it´s
automatically converted to an SQL NULL value.
When a double-quoted string is used and that string is read as the field value, then the field value
is automatically converted to an SQL NULL value.
• trim both whitespace, trim left whitespace, trim right whitespace
This option allows to trim whitespaces in the read data, either from both sides of the data, or only
the whitespace characters found on the left of the streaing, or only those on the right of the
string.
• WITH
When loading from a FIXED file, the following options are supported:
• truncate
When this option is listed, pgloader issues a TRUNCATE command against the PostgreSQL target table
before reading the data file.
• disable triggers
When this option is listed, pgloader issues an ALTER TABLE ... DISABLE TRIGGER ALL command against
the PostgreSQL target table before copying the data, then the command ALTER TABLE ... ENABLE TRIGGER
ALL once the COPY is done.
This option allows loading data into a pre-existing table ignoring the foreign key constraints and
user defined triggers and may result in invalid foreign key constraints once the data is loaded. Use
with care.
• skip header
Takes a numeric value as argument. Instruct pgloader to skip that many lines at the beginning of the
input file.
LOAD COPY FORMATTED FILES
This commands instructs pgloader to load from a file containing COPY TEXT data as described in the
PostgreSQL documentation. Here´s an example:
LOAD COPY
FROM copy://./data/track.copy
(
trackid, track, album, media, genre, composer,
milliseconds, bytes, unitprice
)
INTO postgresql:///pgloader?track_full
WITH truncate
SET work_mem to ´14MB´,
standard_conforming_strings to ´on´
BEFORE LOAD DO
$$ drop table if exists track_full; $$,
$$ create table track_full (
trackid bigserial,
track text,
album text,
media text,
genre text,
composer text,
milliseconds bigint,
bytes bigint,
unitprice numeric
);
$$;
The COPY format command accepts the following clauses and options:
• FROM
Filename where to load the data from. This support local files, HTTP URLs and zip files containing a
single dbf file of the same name. Fetch such a zip file from an HTTP address is of course supported.
• inline
The data is found after the end of the parsed commands. Any number of empty lines between the end of
the commands and the beginning of the data is accepted.
• stdin
Reads the data from the standard input stream.
• FILENAMES MATCHING
The whole matching clause must follow the following rule:
[ ALL FILENAMES | [ FIRST ] FILENAME ]
MATCHING regexp
[ IN DIRECTORY ´...´ ]
The matching clause applies given regular expression (see above for exact syntax, several options can be
used here) to filenames. It´s then possible to load data from only the first match of all of them.
The optional IN DIRECTORY clause allows specifying which directory to walk for finding the data files,
and can be either relative to where the command file is read from, or absolute. The given directory must
exists.
• WITH
When loading from a COPY file, the following options are supported:
• delimiter
Takes a single character as argument, which must be found inside single quotes, and might be given as
the printable character itself, the special value \t to denote a tabulation character, or 0x then an
hexadecimal value read as the ASCII code for the character.
This character is used as the delimiter when reading the data, in a similar way to the PostgreSQL
COPY option.
• null
Takes a quoted string as an argument (quotes can be either double quotes or single quotes) and uses
that string as the NULL representation in the data.
This is similar to the null COPY option in PostgreSQL.
• truncate
When this option is listed, pgloader issues a TRUNCATE command against the PostgreSQL target table
before reading the data file.
• disable triggers
When this option is listed, pgloader issues an ALTER TABLE ... DISABLE TRIGGER ALL command against
the PostgreSQL target table before copying the data, then the command ALTER TABLE ... ENABLE TRIGGER
ALL once the COPY is done.
This option allows loading data into a pre-existing table ignoring the foreign key constraints and
user defined triggers and may result in invalid foreign key constraints once the data is loaded. Use
with care.
• skip header
Takes a numeric value as argument. Instruct pgloader to skip that many lines at the beginning of the
input file.
LOAD DBF
This command instructs pgloader to load data from a DBF file. Here´s an example:
LOAD DBF
FROM http://www.insee.fr/fr/methodes/nomenclatures/cog/telechargement/2013/dbf/reg2013.dbf
INTO postgresql://user@localhost/dbname
WITH truncate, create table;
The dbf format command accepts the following clauses and options:
• FROM
Filename where to load the data from. This support local files, HTTP URLs and zip files containing a
single dbf file of the same name. Fetch such a zip file from an HTTP address is of course supported.
• WITH
When loading from a DBF file, the following options are supported:
• truncate
When this option is listed, pgloader issues a TRUNCATE command against the PostgreSQL target table
before reading the data file.
• disable triggers
When this option is listed, pgloader issues an ALTER TABLE ... DISABLE TRIGGER ALL command against
the PostgreSQL target table before copying the data, then the command ALTER TABLE ... ENABLE TRIGGER
ALL once the COPY is done.
This option allows loading data into a pre-existing table ignoring the foreign key constraints and
user defined triggers and may result in invalid foreign key constraints once the data is loaded. Use
with care.
• create table
When this option is listed, pgloader creates the table using the meta data found in the DBF file,
which must contain a list of fields with their data type. A standard data type conversion from DBF to
PostgreSQL is done.
• table name
This options expects as its value the possibly qualified name of the table to create.
LOAD IXF
This command instructs pgloader to load data from an IBM IXF file. Here´s an example:
LOAD IXF
FROM data/nsitra.test1.ixf
INTO postgresql:///pgloader?nsitra.test1
WITH truncate, create table, timezone UTC
BEFORE LOAD DO
$$ create schema if not exists nsitra; $$,
$$ drop table if exists nsitra.test1; $$;
The ixf format command accepts the following clauses and options:
• FROM
Filename where to load the data from. This support local files, HTTP URLs and zip files containing a
single ixf file of the same name. Fetch such a zip file from an HTTP address is of course supported.
• WITH
When loading from a IXF file, the following options are supported:
• truncate
When this option is listed, pgloader issues a TRUNCATE command against the PostgreSQL target table
before reading the data file.
• disable triggers
When this option is listed, pgloader issues an ALTER TABLE ... DISABLE TRIGGER ALL command against
the PostgreSQL target table before copying the data, then the command ALTER TABLE ... ENABLE TRIGGER
ALL once the COPY is done.
This option allows loading data into a pre-existing table ignoring the foreign key constraints and
user defined triggers and may result in invalid foreign key constraints once the data is loaded. Use
with care.
• create table
When this option is listed, pgloader creates the table using the meta data found in the DBF file,
which must contain a list of fields with their data type. A standard data type conversion from DBF to
PostgreSQL is done.
• table name
This options expects as its value the possibly qualified name of the table to create.
• timezone
This options allows to specify which timezone is used when parsing timestamps from an IXF file, and
defaults to UTC. Expected values are either UTC, GMT or a single quoted location name such as
´Universal´ or ´Europe/Paris´.
LOAD ARCHIVE
This command instructs pgloader to load data from one or more files contained in an archive. Currently
the only supported archive format is ZIP, and the archive might be downloaded from an HTTP URL.
Here´s an example:
LOAD ARCHIVE
FROM /Users/dim/Downloads/GeoLiteCity-latest.zip
INTO postgresql:///ip4r
BEFORE LOAD
DO $$ create extension if not exists ip4r; $$,
$$ create schema if not exists geolite; $$,
EXECUTE ´geolite.sql´
LOAD CSV
FROM FILENAME MATCHING ~/GeoLiteCity-Location.csv/
WITH ENCODING iso-8859-1
(
locId,
country,
region null if blanks,
city null if blanks,
postalCode null if blanks,
latitude,
longitude,
metroCode null if blanks,
areaCode null if blanks
)
INTO postgresql:///ip4r?geolite.location
(
locid,country,region,city,postalCode,
location point using (format nil "(~a,~a)" longitude latitude),
metroCode,areaCode
)
WITH skip header = 2,
fields optionally enclosed by ´"´,
fields escaped by double-quote,
fields terminated by ´,´
AND LOAD CSV
FROM FILENAME MATCHING ~/GeoLiteCity-Blocks.csv/
WITH ENCODING iso-8859-1
(
startIpNum, endIpNum, locId
)
INTO postgresql:///ip4r?geolite.blocks
(
iprange ip4r using (ip-range startIpNum endIpNum),
locId
)
WITH skip header = 2,
fields optionally enclosed by ´"´,
fields escaped by double-quote,
fields terminated by ´,´
FINALLY DO
$$ create index blocks_ip4r_idx on geolite.blocks using gist(iprange); $$;
The archive command accepts the following clauses and options:
• FROM
Filename or HTTP URI where to load the data from. When given an HTTP URL the linked file will get
downloaded locally before processing.
If the file is a zip file, the command line utility unzip is used to expand the archive into files in
$TMPDIR, or /tmp if $TMPDIR is unset or set to a non-existing directory.
Then the following commands are used from the top level directory where the archive has been
expanded.
• command [ AND command ... ]
A series of commands against the contents of the archive, at the moment only CSV,´FIXED and DBF
commands are supported.
Note that commands are supporting the clause FROM FILENAME MATCHING which allows the pgloader command
not to depend on the exact names of the archive directories.
The same clause can also be applied to several files with using the spelling FROM ALL FILENAMES
MATCHING and a regular expression.
The whole matching clause must follow the following rule:
FROM [ ALL FILENAMES | [ FIRST ] FILENAME ] MATCHING
• FINALLY DO
SQL Queries to run once the data is loaded, such as CREATE INDEX.
LOAD MYSQL DATABASE
This command instructs pgloader to load data from a database connection. The only supported database
source is currently MySQL, and pgloader supports dynamically converting the schema of the source database
and the indexes building.
A default set of casting rules are provided and might be overloaded and appended to by the command.
Here´s an example using as many options as possible, some of them even being defaults. Chances are you
don´t need that complex a setup, don´t copy and paste it, use it only as a reference!
LOAD DATABASE
FROM mysql://root@localhost/sakila
INTO postgresql://localhost:54393/sakila
WITH include drop, create tables, create indexes, reset sequences,
workers = 8, concurrency = 1,
multiple readers per thread, rows per range = 50000
SET PostgreSQL PARAMETERS
maintenance_work_mem to ´128MB´,
work_mem to ´12MB´,
search_path to ´sakila, public, "$user"´
SET MySQL PARAMETERS
net_read_timeout = ´120´,
net_write_timeout = ´120´
CAST type bigint when (= precision 20) to bigserial drop typemod,
type date drop not null drop default using zero-dates-to-null,
-- type tinyint to boolean using tinyint-to-boolean,
type year to integer
MATERIALIZE VIEWS film_list, staff_list
-- INCLUDING ONLY TABLE NAMES MATCHING ~/film/, ´actor´
-- EXCLUDING TABLE NAMES MATCHING ~<ory>
-- DECODING TABLE NAMES MATCHING ~/messed/, ~/encoding/ AS utf8
-- ALTER TABLE NAMES MATCHING ´film´ RENAME TO ´films´
-- ALTER TABLE NAMES MATCHING ~/_list$/ SET SCHEMA ´mv´
ALTER TABLE NAMES MATCHING ~/_list$/, ´sales_by_store´, ~/sales_by/
SET SCHEMA ´mv´
ALTER TABLE NAMES MATCHING ´film´ RENAME TO ´films´
ALTER TABLE NAMES MATCHING ~/./ SET (fillfactor=´40´)
ALTER SCHEMA ´sakila´ RENAME TO ´pagila´
BEFORE LOAD DO
$$ create schema if not exists pagila; $$,
$$ create schema if not exists mv; $$,
$$ alter database sakila set search_path to pagila, mv, public; $$;
The database command accepts the following clauses and options:
• FROM
Must be a connection URL pointing to a MySQL database.
If the connection URI contains a table name, then only this table is migrated from MySQL to
PostgreSQL.
See the SOURCE CONNECTION STRING section above for details on how to write the connection string.
Environment variables described in http://dev.mysql.com/doc/refman/5.0/en/environment-variables.html
can be used as default values too. If the user is not provided, then it defaults to USER environment
variable value. The password can be provided with the environment variable MYSQL_PWD. The host can be
provided with the environment variable MYSQL_HOST and otherwise defaults to localhost. The port can
be provided with the environment variable MYSQL_TCP_PORT and otherwise defaults to 3306.
• WITH
When loading from a MySQL database, the following options are supported, and the default WITH clause
is: no truncate, create schema, create tables, include drop, create indexes, reset sequences, foreign
keys, downcase identifiers, uniquify index names.
WITH options:
• include drop
When this option is listed, pgloader drops all the tables in the target PostgreSQL database whose
names appear in the MySQL database. This option allows for using the same command several times in a
row until you figure out all the options, starting automatically from a clean environment. Please
note that CASCADE is used to ensure that tables are dropped even if there are foreign keys pointing
to them. This is precisely what include drop is intended to do: drop all target tables and recreate
them.
Great care needs to be taken when using include drop, as it will cascade to all objects referencing
the target tables, possibly including other tables that are not being loaded from the source DB.
• include no drop
When this option is listed, pgloader will not include any DROP statement when loading the data.
• truncate
When this option is listed, pgloader issue the TRUNCATE command against each PostgreSQL table just
before loading data into it.
• no truncate
When this option is listed, pgloader issues no TRUNCATE command.
• disable triggers
When this option is listed, pgloader issues an ALTER TABLE ... DISABLE TRIGGER ALL command against
the PostgreSQL target table before copying the data, then the command ALTER TABLE ... ENABLE TRIGGER
ALL once the COPY is done.
This option allows loading data into a pre-existing table ignoring the foreign key constraints and
user defined triggers and may result in invalid foreign key constraints once the data is loaded. Use
with care.
• create tables
When this option is listed, pgloader creates the table using the meta data found in the MySQL file,
which must contain a list of fields with their data type. A standard data type conversion from DBF to
PostgreSQL is done.
• create no tables
When this option is listed, pgloader skips the creation of table before loading data, target tables
must then already exist.
Also, when using create no tables pgloader fetches the metadata from the current target database and
checks type casting, then will remove constraints and indexes prior to loading the data and install
them back again once the loading is done.
• create indexes
When this option is listed, pgloader gets the definitions of all the indexes found in the MySQL
database and create the same set of index definitions against the PostgreSQL database.
• create no indexes
When this option is listed, pgloader skips the creating indexes.
• drop indexes
When this option is listed, pgloader drops the indexes in the target database before loading the
data, and creates them again at the end of the data copy.
• uniquify index names, preserve index names
MySQL index names are unique per-table whereas in PostgreSQL index names have to be unique
per-schema. The default for pgloader is to change the index name by prefixing it with idx_OID where
OID is the internal numeric identifier of the table the index is built against.
In somes cases like when the DDL are entirely left to a framework it might be sensible for pgloader
to refrain from handling index unique names, that is achieved by using the preserve index names
option.
The default is to uniquify index names.
Even when using the option preserve index names, MySQL primary key indexes named "PRIMARY" will get
their names uniquified. Failing to do so would prevent the primary keys to be created again in
PostgreSQL where the index names must be unique per schema.
• foreign keys
When this option is listed, pgloader gets the definitions of all the foreign keys found in the MySQL
database and create the same set of foreign key definitions against the PostgreSQL database.
• no foreign keys
When this option is listed, pgloader skips creating foreign keys.
• reset sequences
When this option is listed, at the end of the data loading and after the indexes have all been
created, pgloader resets all the PostgreSQL sequences created to the current maximum value of the
column they are attached to.
The options schema only and data only have no effects on this option.
• reset no sequences
When this option is listed, pgloader skips resetting sequences after the load.
The options schema only and data only have no effects on this option.
• downcase identifiers
When this option is listed, pgloader converts all MySQL identifiers (table names, index names, column
names) to downcase, except for PostgreSQL reserved keywords.
The PostgreSQL reserved keywords are determined dynamically by using the system function
pg_get_keywords().
• quote identifiers
When this option is listed, pgloader quotes all MySQL identifiers so that their case is respected.
Note that you will then have to do the same thing in your application code queries.
• schema only
When this option is listed pgloader refrains from migrating the data over. Note that the schema in
this context includes the indexes when the option create indexes has been listed.
• data only
When this option is listed pgloader only issues the COPY statements, without doing any other
processing.
• single reader per thread, multiple readers per thread
The default is single reader per thread and it means that each MySQL table is read by a single thread
as a whole, with a single SELECT statement using no WHERE clause.
When using multiple readers per thread pgloader may be able to divide the reading work into several
threads, as many as the concurrency setting, which needs to be greater than 1 for this option to kick
be activated.
For each source table, pgloader searches for a primary key over a single numeric column, or a
multiple-column primary key index for which the first column is of a numeric data type (one of
integer or bigint). When such an index exists, pgloader runs a query to find the min and max values
on this column, and then split that range into many ranges containing a maximum of rows per range.
When the range list we then obtain contains at least as many ranges than our concurrency setting,
then we distribute those ranges to each reader thread.
So when all the conditions are met, pgloader then starts as many reader thread as the concurrency
setting, and each reader thread issues several queries with a WHERE id >= x AND id < y, where y - x =
rows per range or less (for the last range, depending on the max value just obtained.
• rows per range
How many rows are fetched per SELECT query when using multiple readers per thread, see above for
details.
• SET MySQL PARAMETERS
The SET MySQL PARAMETERS allows setting MySQL parameters using the MySQL SET command each time
pgloader connects to it.
• CAST
The cast clause allows to specify custom casting rules, either to overload the default casting rules
or to amend them with special cases.
A casting rule is expected to follow one of the forms:
type <mysql-type-name> [ <guard> ... ] to <pgsql-type-name> [ <option> ... ]
column <table-name>.<column-name> [ <guards> ] to ...
It´s possible for a casting rule to either match against a MySQL data type or against a given column name
in a given table name. That flexibility allows to cope with cases where the type tinyint might have been
used as a boolean in some cases but as a smallint in others.
The casting rules are applied in order, the first match prevents following rules to be applied, and user
defined rules are evaluated first.
The supported guards are:
• when default ´value´
The casting rule is only applied against MySQL columns of the source type that have given value,
which must be a single-quoted or a double-quoted string.
• when typemod expression
The casting rule is only applied against MySQL columns of the source type that have a typemod value
matching the given typemod expression. The typemod is separated into its precision and scale
components.
Example of a cast rule using a typemod guard:
type char when (= precision 1) to char keep typemod
This expression casts MySQL char(1) column to a PostgreSQL column of type char(1) while allowing for the
general case char(N) will be converted by the default cast rule into a PostgreSQL type varchar(N).
• with extra auto_increment
The casting rule is only applied against MySQL columns having the extra column auto_increment option
set, so that it´s possible to target e.g. serial rather than integer.
The default matching behavior, when this option isn´t set, is to match both columns with the extra
definition and without.
This means that if you want to implement a casting rule that target either serial or integer from a
smallint definition depending on the auto_increment extra bit of information from MySQL, then you
need to spell out two casting rules as following:
type smallint with extra auto_increment
to serial drop typemod keep default keep not null,
type smallint
to integer drop typemod keep default keep not null
The supported casting options are:
• drop default, keep default
When the option drop default is listed, pgloader drops any existing default expression in the MySQL
database for columns of the source type from the CREATE TABLE statement it generates.
The spelling keep default explicitly prevents that behaviour and can be used to overload the default
casting rules.
• drop not null, keep not null, set not null
When the option drop not null is listed, pgloader drops any existing NOT NULL constraint associated
with the given source MySQL datatype when it creates the tables in the PostgreSQL database.
The spelling keep not null explicitly prevents that behaviour and can be used to overload the default
casting rules.
When the option set not null is listed, pgloader sets a NOT NULL constraint on the target column
regardless whether it has been set in the source MySQL column.
• drop typemod, keep typemod
When the option drop typemod is listed, pgloader drops any existing typemod definition (e.g.
precision and scale) from the datatype definition found in the MySQL columns of the source type when
it created the tables in the PostgreSQL database.
The spelling keep typemod explicitly prevents that behaviour and can be used to overload the default
casting rules.
• using
This option takes as its single argument the name of a function to be found in the
pgloader.transforms Common Lisp package. See above for details.
It´s possible to augment a default cast rule (such as one that applies against ENUM data type for
example) with a transformation function by omitting entirely the type parts of the casting rule, as
in the following example:
column enumerate.foo using empty-string-to-null
• MATERIALIZE VIEWS
This clause allows you to implement custom data processing at the data source by providing a view
definition against which pgloader will query the data. It´s not possible to just allow for plain SQL
because we want to know a lot about the exact data types of each column involved in the query output.
This clause expect a comma separated list of view definitions, each one being either the name of an
existing view in your database or the following expression:
name AS $$ sql query $$
The name and the sql query will be used in a CREATE VIEW statement at the beginning of the data
loading, and the resulting view will then be dropped at the end of the data loading.
• MATERIALIZE ALL VIEWS
Same behaviour as MATERIALIZE VIEWS using the dynamic list of views as returned by MySQL rather than
asking the user to specify the list.
• INCLUDING ONLY TABLE NAMES MATCHING
Introduce a comma separated list of table names or regular expression used to limit the tables to
migrate to a sublist.
Example:
INCLUDING ONLY TABLE NAMES MATCHING ~/film/, ´actor´
• EXCLUDING TABLE NAMES MATCHING
Introduce a comma separated list of table names or regular expression used to exclude table names
from the migration. This filter only applies to the result of the INCLUDING filter.
EXCLUDING TABLE NAMES MATCHING ~<ory>
• DECODING TABLE NAMES MATCHING
Introduce a comma separated list of table names or regular expressions used to force the encoding to
use when processing data from MySQL. If the data encoding known to you is different from MySQL´s idea
about it, this is the option to use.
DECODING TABLE NAMES MATCHING ~/messed/, ~/encoding/ AS utf8
You can use as many such rules as you need, all with possibly different encodings.
• ALTER TABLE NAMES MATCHING
Introduce a comma separated list of table names or regular expressions that you want to target in the
pgloader ALTER TABLE command. The only two available actions are SET SCHEMA and RENAME TO, both take
a quoted string as parameter:
ALTER TABLE NAMES MATCHING ~/_list$/, ´sales_by_store´, ~/sales_by/
SET SCHEMA ´mv´
ALTER TABLE NAMES MATCHING ´film´ RENAME TO ´films´
ALTER TABLE NAMES MATCHING ~/./ SET (fillfactor=´40´)
You can use as many such rules as you need. The list of tables to be migrated is searched in pgloader
memory against the ALTER TABLE matching rules, and for each command pgloader stops at the first matching
criteria (regexp or string).
No ALTER TABLE command is sent to PostgreSQL, the modification happens at the level of the pgloader
in-memory representation of your source database schema. In case of a name change, the mapping is kept
and reused in the foreign key and index support.
The SET () action takes effect as a WITH clause for the CREATE TABLE command that pgloader will run when
it has to create a table.
LIMITATIONS
The database command currently only supports MySQL source database and has the following limitations:
• Views are not migrated,
Supporting views might require implementing a full SQL parser for the MySQL dialect with a porting
engine to rewrite the SQL against PostgreSQL, including renaming functions and changing some
constructs.
While it´s not theoretically impossible, don´t hold your breath.
• Triggers are not migrated
The difficulty of doing so is not yet assessed.
• ON UPDATE CURRENT_TIMESTAMP is currently not migrated
It´s simple enough to implement, just not on the priority list yet.
• Of the geometric datatypes, only the POINT database has been covered. The other ones should be easy
enough to implement now, it´s just not done yet.
DEFAULT MySQL CASTING RULES
When migrating from MySQL the following Casting Rules are provided:
Numbers:
• type int with extra auto_increment to serial when (< precision 10)
• type int with extra auto_increment to bigserial when (<= 10 precision)
• type int to int when (< precision 10)
• type int to bigint when (<= 10 precision)
• type tinyint with extra auto_increment to serial
• type smallint with extra auto_increment to serial
• type mediumint with extra auto_increment to serial
• type bigint with extra auto_increment to bigserial
• type tinyint to boolean when (= 1 precision) using tinyint-to-boolean
• type tinyint to smallint drop typemod
• type smallint to smallint drop typemod
• type mediumint to integer drop typemod
• type integer to integer drop typemod
• type float to float drop typemod
• type bigint to bigint drop typemod
• type double to double precision drop typemod
• type numeric to numeric keep typemod
• type decimal to decimal keep typemod
Texts:
• type char to char keep typemod using remove-null-characters
• type varchar to varchar keep typemod using remove-null-characters
• type tinytext to text using remove-null-characters
• type text to text using remove-null-characters
• type mediumtext to text using remove-null-characters
• type longtext to text using remove-null-characters
Binary:
• type binary to bytea
• type varbinary to bytea
• type tinyblob to bytea
• type blob to bytea
• type mediumblob to bytea
• type longblob to bytea
Date:
• type datetime when default "0000-00-00 00:00:00" and not null to timestamptz drop not null drop
default using zero-dates-to-null
• type datetime when default "0000-00-00 00:00:00" to timestamptz drop default using zero-dates-to-null
• type timestamp when default "0000-00-00 00:00:00" and not null to timestamptz drop not null drop
default using zero-dates-to-null
• type timestamp when default "0000-00-00 00:00:00" to timestamptz drop default using
zero-dates-to-null
• type date when default "0000-00-00" to date drop default using zero-dates-to-null
• type date to date
• type datetime to timestamptz
• type timestamp to timestamptz
• type year to integer drop typemod
Geometric:
• type point to point using pgloader.transforms::convert-mysql-point
Enum types are declared inline in MySQL and separately with a CREATE TYPE command in PostgreSQL, so each
column of Enum Type is converted to a type named after the table and column names defined with the same
labels in the same order.
When the source type definition is not matched in the default casting rules nor in the casting rules
provided in the command, then the type name with the typemod is used.
LOAD SQLite DATABASE
This command instructs pgloader to load data from a SQLite file. Automatic discovery of the schema is
supported, including build of the indexes.
Here´s an example:
load database
from sqlite:///Users/dim/Downloads/lastfm_tags.db
into postgresql:///tags
with include drop, create tables, create indexes, reset sequences
set work_mem to ´16MB´, maintenance_work_mem to ´512 MB´;
The sqlite command accepts the following clauses and options:
• FROM
Path or HTTP URL to a SQLite file, might be a .zip file.
• WITH
When loading from a SQLite database, the following options are supported:
When loading from a SQLite database, the following options are supported, and the default WITH clause
is: no truncate, create tables, include drop, create indexes, reset sequences, downcase identifiers,
encoding ´utf-8´.
• include drop
When this option is listed, pgloader drops all the tables in the target PostgreSQL database whose
names appear in the SQLite database. This option allows for using the same command several times in a
row until you figure out all the options, starting automatically from a clean environment. Please
note that CASCADE is used to ensure that tables are dropped even if there are foreign keys pointing
to them. This is precisely what include drop is intended to do: drop all target tables and recreate
them.
Great care needs to be taken when using include drop, as it will cascade to all objects referencing
the target tables, possibly including other tables that are not being loaded from the source DB.
• include no drop
When this option is listed, pgloader will not include any DROP statement when loading the data.
• truncate
When this option is listed, pgloader issue the TRUNCATE command against each PostgreSQL table just
before loading data into it.
• no truncate
When this option is listed, pgloader issues no TRUNCATE command.
• disable triggers
When this option is listed, pgloader issues an ALTER TABLE ... DISABLE TRIGGER ALL command against
the PostgreSQL target table before copying the data, then the command ALTER TABLE ... ENABLE TRIGGER
ALL once the COPY is done.
This option allows loading data into a pre-existing table ignoring the foreign key constraints and
user defined triggers and may result in invalid foreign key constraints once the data is loaded. Use
with care.
• create tables
When this option is listed, pgloader creates the table using the meta data found in the SQLite file,
which must contain a list of fields with their data type. A standard data type conversion from DBF to
PostgreSQL is done.
• create no tables
When this option is listed, pgloader skips the creation of table before loading data, target tables
must then already exist.
Also, when using create no tables pgloader fetches the metadata from the current target database and
checks type casting, then will remove constraints and indexes prior to loading the data and install
them back again once the loading is done.
• create indexes
When this option is listed, pgloader gets the definitions of all the indexes found in the SQLite
database and create the same set of index definitions against the PostgreSQL database.
• create no indexes
When this option is listed, pgloader skips the creating indexes.
• drop indexes
When this option is listed, pgloader drops the indexes in the target database before loading the
data, and creates them again at the end of the data copy.
• reset sequences
When this option is listed, at the end of the data loading and after the indexes have all been
created, pgloader resets all the PostgreSQL sequences created to the current maximum value of the
column they are attached to.
• reset no sequences
When this option is listed, pgloader skips resetting sequences after the load.
The options schema only and data only have no effects on this option.
• schema only
When this option is listed pgloader will refrain from migrating the data over. Note that the schema
in this context includes the indexes when the option create indexes has been listed.
• data only
When this option is listed pgloader only issues the COPY statements, without doing any other
processing.
• encoding
This option allows to control which encoding to parse the SQLite text data with. Defaults to UTF-8.
• CAST
The cast clause allows to specify custom casting rules, either to overload the default casting rules
or to amend them with special cases.
Please refer to the MySQL CAST clause for details.
• INCLUDING ONLY TABLE NAMES LIKE
Introduce a comma separated list of table name patterns used to limit the tables to migrate to a
sublist.
Example:
INCLUDING ONLY TABLE NAMES LIKE ´Invoice%´
• EXCLUDING TABLE NAMES LIKE
Introduce a comma separated list of table name patterns used to exclude table names from the
migration. This filter only applies to the result of the INCLUDING filter.
EXCLUDING TABLE NAMES LIKE ´appointments´
DEFAULT SQLite CASTING RULES
When migrating from SQLite the following Casting Rules are provided:
Numbers:
• type tinyint to smallint using integer-to-string
• type integer to bigint using integer-to-string
• type float to float using float-to-string
• type real to real using float-to-string
• type double to double precision using float-to-string
• type numeric to numeric using float-to-string
Texts:
• type character to text drop typemod
• type varchar to text drop typemod
• type nvarchar to text drop typemod
• type char to text drop typemod
• type nchar to text drop typemod
• type nvarchar to text drop typemod
• type clob to text drop typemod
Binary:
• type blob to bytea
Date:
• type datetime to timestamptz using sqlite-timestamp-to-timestamp
• type timestamp to timestamptz using sqlite-timestamp-to-timestamp
• type timestamptz to timestamptz using sqlite-timestamp-to-timestamp
LOAD MS SQL DATABASE
This command instructs pgloader to load data from a MS SQL database. Automatic discovery of the schema is
supported, including build of the indexes, primary and foreign keys constraints.
Here´s an example:
load database
from mssql://user@host/dbname
into postgresql:///dbname
including only table names like ´GlobalAccount´ in schema ´dbo´
set work_mem to ´16MB´, maintenance_work_mem to ´512 MB´
before load do $$ drop schema if exists dbo cascade; $$;
The mssql command accepts the following clauses and options:
• FROM
Connection string to an existing MS SQL database server that listens and welcome external TCP/IP
connection. As pgloader currently piggybacks on the FreeTDS driver, to change the port of the server
please export the TDSPORT environment variable.
• WITH
When loading from a MS SQL database, the same options as when loading a MySQL database are supported.
Please refer to the MySQL section. The following options are added:
• create schemas
When this option is listed, pgloader creates the same schemas as found on the MS SQL instance. This
is the default.
• create no schemas
When this option is listed, pgloader refrains from creating any schemas at all, you must then ensure
that the target schema do exist.
• CAST
The cast clause allows to specify custom casting rules, either to overload the default casting rules
or to amend them with special cases.
Please refer to the MySQL CAST clause for details.
• INCLUDING ONLY TABLE NAMES LIKE ´...´ [, ´...´] IN SCHEMA ´...´
Introduce a comma separated list of table name patterns used to limit the tables to migrate to a
sublist. More than one such clause may be used, they will be accumulated together.
Example:
including only table names lile ´GlobalAccount´ in schema ´dbo´
• EXCLUDING TABLE NAMES LIKE ´...´ [, ´...´] IN SCHEMA ´...´
Introduce a comma separated list of table name patterns used to exclude table names from the
migration. This filter only applies to the result of the INCLUDING filter.
EXCLUDING TABLE NAMES MATCHING ´LocalAccount´ in schema ´dbo´
• ALTER SCHEMA ´...´ RENAME TO ´...´
Allows to rename a schema on the flight, so that for instance the tables found in the schema ´dbo´ in
your source database will get migrated into the schema ´public´ in the target database with this
command:
ALTER SCHEMA ´dbo´ RENAME TO ´public´
• ALTER TABLE NAMES MATCHING ... IN SCHEMA ´...´
See the MySQL explanation for this clause above. It works the same in the context of migrating from
MS SQL, only with the added option to specify the name of the schema where to find the definition of
the target tables.
The matching is done in pgloader itself, with a Common Lisp regular expression lib, so doesn´t depend
on the LIKE implementation of MS SQL, nor on the lack of support for regular expressions in the
engine.
Driver setup and encoding
pgloader is using the FreeTDS driver, and internally expects the data to be sent in utf-8. To achieve
that, you can configure the FreeTDS driver with those defaults, in the file ~/.freetds.conf:
[global]
tds version = 7.4
client charset = UTF-8
DEFAULT MS SQL CASTING RULES
When migrating from MS SQL the following Casting Rules are provided:
Numbers:
• type tinyint to smallint
• type float to float using float-to-string
• type real to real using float-to-string
• type double to double precision using float-to-string
• type numeric to numeric using float-to-string
• type decimal to numeric using float-to-string
• type money to numeric using float-to-string
• type smallmoney to numeric using float-to-string
Texts:
• type char to text drop typemod
• type nchat to text drop typemod
• type varchar to text drop typemod
• type nvarchar to text drop typemod
• type xml to text drop typemod
Binary:
• type binary to bytea using byte-vector-to-bytea
• type varbinary to bytea using byte-vector-to-bytea
Date:
• type datetime to timestamptz
• type datetime2 to timestamptz
Others:
• type bit to boolean
• type hierarchyid to bytea
• type geography to bytea
• type uniqueidentifier to uuid using sql-server-uniqueidentifier-to-uuid
TRANSFORMATION FUNCTIONS
Some data types are implemented in a different enough way that a transformation function is necessary.
This function must be written in Common lisp and is searched in the pgloader.transforms package.
Some default transformation function are provided with pgloader, and you can use the --load command line
option to load and compile your own lisp file into pgloader at runtime. For your functions to be found,
remember to begin your lisp file with the following form:
(in-package #:pgloader.transforms)
The provided transformation functions are:
• zero-dates-to-null
When the input date is all zeroes, return nil, which gets loaded as a PostgreSQL NULL value.
• date-with-no-separator
Applies zero-dates-to-null then transform the given date into a format that PostgreSQL will actually
process:
In: "20041002152952"
Out: "2004-10-02 15:29:52"
• time-with-no-separator
Transform the given time into a format that PostgreSQL will actually process:
In: "08231560"
Out: "08:23:15.60"
• tinyint-to-boolean
As MySQL lacks a proper boolean type, tinyint is often used to implement that. This function
transforms 0 to ´false´ and anything else to ´true´.
• bits-to-boolean
As MySQL lacks a proper boolean type, BIT is often used to implement that. This function transforms
1-bit bit vectors from 0 to f and any other value to t..
• int-to-ip
Convert an integer into a dotted representation of an ip4.
In: 18435761
Out: "1.25.78.177"
• ip-range
Converts a couple of integers given as strings into a range of ip4.
In: "16825344" "16825599"
Out: "1.0.188.0-1.0.188.255"
• convert-mysql-point
Converts from the astext representation of points in MySQL to the PostgreSQL representation.
In: "POINT(48.5513589 7.6926827)"
Out: "(48.5513589,7.6926827)"
• integer-to-string
Converts a integer string or a Common Lisp integer into a string suitable for a PostgreSQL integer.
Takes care of quoted integers.
In: "\"0\""
Out: "0"
• float-to-string
Converts a Common Lisp float into a string suitable for a PostgreSQL float:
In: 100.0d0
Out: "100.0"
• set-to-enum-array
Converts a string representing a MySQL SET into a PostgreSQL Array of Enum values from the set.
In: "foo,bar"
Out: "{foo,bar}"
• empty-string-to-null
Convert an empty string to a null.
• right-trim
Remove whitespace at end of string.
• remove-null-characters
Remove NUL characters (0x0) from given strings.
• byte-vector-to-bytea
Transform a simple array of unsigned bytes to the PostgreSQL bytea Hex Format representation as
documented at http://www.postgresql.org/docs/9.3/interactive/datatype-binary.html
• sqlite-timestamp-to-timestamp
SQLite type system is quite interesting, so cope with it here to produce timestamp literals as
expected by PostgreSQL. That covers year only on 4 digits, 0 dates to null, and proper date strings.
• sql-server-uniqueidentifier-to-uuid
The SQL Server driver receives data fo type uniqueidentifier as byte vector that we then need to
convert to an UUID string for PostgreSQL COPY input format to process.
• unix-timestamp-to-timestamptz
Converts a unix timestamp (number of seconds elapsed since beginning of 1970) into a proper
PostgreSQL timestamp format.
• varbinary-to-string
Converts binary encoded string (such as a MySQL varbinary entry) to a decoded text, using the table´s
encoding that may be overloaded with the DECODING TABLE NAMES MATCHING clause.
LOAD MESSAGES
This command is still experimental and allows receiving messages via UDP using a syslog like format, and,
depending on rule matching, loads named portions of the data stream into a destination table.
LOAD MESSAGES
FROM syslog://localhost:10514/
WHEN MATCHES rsyslog-msg IN apache
REGISTERING timestamp, ip, rest
INTO postgresql://localhost/db?logs.apache
SET guc_1 = ´value´, guc_2 = ´other value´
WHEN MATCHES rsyslog-msg IN others
REGISTERING timestamp, app-name, data
INTO postgresql://localhost/db?logs.others
SET guc_1 = ´value´, guc_2 = ´other value´
WITH apache = rsyslog
DATA = IP REST
IP = 1*3DIGIT "." 1*3DIGIT "."1*3DIGIT "."1*3DIGIT
REST = ~/.*/
WITH others = rsyslog;
As the command is still experimental the options might be changed in the future and the details are not
documented.
AUTHOR
Dimitri Fontaine dimitri@2ndQuadrant.fr
SEE ALSO
PostgreSQL COPY documentation at http://www.postgresql.org/docs/9.3/static/sql-copy.html.
The pgloader source code, binary packages, documentation and examples may be downloaded from
http://pgloader.io/.
ff July 2017 PGLOADER(1)