Provided by: percona-toolkit_3.0.13-1_all bug

NAME

       pt-fingerprint - Convert queries into fingerprints.

SYNOPSIS

       Usage: pt-fingerprint [OPTIONS] [FILES]

       pt-fingerprint converts queries into fingerprints.  With the --query option, converts the
       option's value into a fingerprint.  With no options, treats command-line arguments as
       FILEs and reads and converts semicolon-separated queries from the FILEs. When FILE is -,
       it read standard input.

       Convert a single query:

         pt-fingerprint --query "select a, b, c from users where id = 500"

       Convert a file full of queries:

         pt-fingerprint /path/to/file.txt

RISKS

       Percona Toolkit is mature, proven in the real world, and well tested, but all database
       tools can pose a risk to the system and the database server.  Before using this tool,
       please:

       ·   Read the tool's documentation

       ·   Review the tool's known "BUGS"

       ·   Test the tool on a non-production server

       ·   Backup your production server and verify the backups

DESCRIPTION

       A query fingerprint is the abstracted form of a query, which makes it possible to group
       similar queries together.  Abstracting a query removes literal values, normalizes
       whitespace, and so on.  For example, consider these two queries:

         SELECT name, password FROM user WHERE id='12823';
         select name,   password from user
            where id=5;

       Both of those queries will fingerprint to

         select name, password from user where id=?

       Once the query's fingerprint is known, we can then talk about a query as though it
       represents all similar queries.

       Query fingerprinting accommodates a great many special cases, which have proven necessary
       in the real world.  For example, an IN list with 5 literals is really equivalent to one
       with 4 literals, so lists of literals are collapsed to a single one.  If you want to
       understand more about how and why all of these cases are handled, please review the test
       cases in the Subversion repository.  If you find something that is not fingerprinted
       properly, please submit a bug report with a reproducible test case.  Here is a list of
       transformations during fingerprinting, which might not be exhaustive:

       ·   Group all SELECT queries from mysqldump together, even if they are against different
           tables.  Ditto for all of pt-table-checksum's checksum queries.

       ·   Shorten multi-value INSERT statements to a single VALUES() list.

       ·   Strip comments.

       ·   Abstract the databases in USE statements, so all USE statements are grouped together.

       ·   Replace all literals, such as quoted strings.  For efficiency, the code that replaces
           literal numbers is somewhat non-selective, and might replace some things as numbers
           when they really are not.  Hexadecimal literals are also replaced.  NULL is treated as
           a literal.  Numbers embedded in identifiers are also replaced, so tables named
           similarly will be fingerprinted to the same values (e.g. users_2009 and users_2010
           will fingerprint identically).

       ·   Collapse all whitespace into a single space.

       ·   Lowercase the entire query.

       ·   Replace all literals inside of IN() and VALUES() lists with a single placeholder,
           regardless of cardinality.

       ·   Collapse multiple identical UNION queries into a single one.

OPTIONS

       This tool accepts additional command-line arguments.  Refer to the "SYNOPSIS" and usage
       information for details.

       --config
           type: Array

           Read this comma-separated list of config files; if specified, this must be the first
           option on the command line.

       --help
           Show help and exit.

       --match-embedded-numbers
           Match numbers embedded in words and replace as single values.  This option causes the
           tool to be more careful about matching numbers so that words with numbers, like
           "catch22" are matched and replaced as a single "?"  placeholder.  Otherwise the
           default number matching pattern will replace "catch22" as "catch?".

           This is helpful if database or table names contain numbers.

       --match-md5-checksums
           Match MD5 checksums and replace as single values.  This option causes the tool to be
           more careful about matching numbers so that MD5 checksums like
           "fbc5e685a5d3d45aa1d0347fdb7c4d35" are matched and replaced as a single "?"
           placeholder.  Otherwise, the default number matching pattern will replace
           "fbc5e685a5d3d45aa1d0347fdb7c4d35" as "fbc?".

       --query
           type: string

           The query to convert into a fingerprint.

       --version
           Show version and exit.

ENVIRONMENT

       The environment variable "PTDEBUG" enables verbose debugging output to STDERR.  To enable
       debugging and capture all output to a file, run the tool like:

          PTDEBUG=1 pt-fingerprint ... > FILE 2>&1

       Be careful: debugging output is voluminous and can generate several megabytes of output.

SYSTEM REQUIREMENTS

       You need Perl, DBI, DBD::mysql, and some core packages that ought to be installed in any
       reasonably new version of Perl.

BUGS

       For a list of known bugs, see <http://www.percona.com/bugs/pt-fingerprint>.

       Please report bugs at <https://jira.percona.com/projects/PT>.  Include the following
       information in your bug report:

       ·   Complete command-line used to run the tool

       ·   Tool "--version"

       ·   MySQL version of all servers involved

       ·   Output from the tool including STDERR

       ·   Input files (log/dump/config files, etc.)

       If possible, include debugging output by running the tool with "PTDEBUG"; see
       "ENVIRONMENT".

DOWNLOADING

       Visit <http://www.percona.com/software/percona-toolkit/> to download the latest release of
       Percona Toolkit.  Or, get the latest release from the command line:

          wget percona.com/get/percona-toolkit.tar.gz

          wget percona.com/get/percona-toolkit.rpm

          wget percona.com/get/percona-toolkit.deb

       You can also get individual tools from the latest release:

          wget percona.com/get/TOOL

       Replace "TOOL" with the name of any tool.

AUTHORS

       Baron Schwartz and Daniel Nichter

ABOUT PERCONA TOOLKIT

       This tool is part of Percona Toolkit, a collection of advanced command-line tools for
       MySQL developed by Percona.  Percona Toolkit was forked from two projects in June, 2011:
       Maatkit and Aspersa.  Those projects were created by Baron Schwartz and primarily
       developed by him and Daniel Nichter.  Visit <http://www.percona.com/software/> to learn
       about other free, open-source software from Percona.

COPYRIGHT, LICENSE, AND WARRANTY

       This program is copyright 2011-2018 Percona LLC and/or its affiliates.

       THIS PROGRAM IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING,
       WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
       PURPOSE.

       This program is free software; you can redistribute it and/or modify it under the terms of
       the GNU General Public License as published by the Free Software Foundation, version 2; OR
       the Perl Artistic License.  On UNIX and similar systems, you can issue `man perlgpl' or
       `man perlartistic' to read these licenses.

       You should have received a copy of the GNU General Public License along with this program;
       if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,
       MA  02111-1307  USA.

VERSION

       pt-fingerprint 3.0.13