Provided by: postgresql-client-9.1_9.1.1-1_i386 bug

NAME

       CREATE_TABLE - define a new table

SYNOPSIS

       CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } | UNLOGGED ] TABLE [ IF NOT EXISTS ] table_name ( [
         { column_name data_type [ COLLATE collation ] [ column_constraint [ ... ] ]
           | table_constraint
           | LIKE parent_table [ like_option ... ] }
           [, ... ]
       ] )
       [ INHERITS ( parent_table [, ... ] ) ]
       [ WITH ( storage_parameter [= value] [, ... ] ) | WITH OIDS | WITHOUT OIDS ]
       [ ON COMMIT { PRESERVE ROWS | DELETE ROWS | DROP } ]
       [ TABLESPACE tablespace ]

       CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } | UNLOGGED ] TABLE [ IF NOT EXISTS ] table_name
           OF type_name [ (
         { column_name WITH OPTIONS [ column_constraint [ ... ] ]
           | table_constraint }
           [, ... ]
       ) ]
       [ WITH ( storage_parameter [= value] [, ... ] ) | WITH OIDS | WITHOUT OIDS ]
       [ ON COMMIT { PRESERVE ROWS | DELETE ROWS | DROP } ]
       [ TABLESPACE tablespace ]

       where column_constraint is:

       [ CONSTRAINT constraint_name ]
       { NOT NULL |
         NULL |
         CHECK ( expression ) |
         DEFAULT default_expr |
         UNIQUE index_parameters |
         PRIMARY KEY index_parameters |
         REFERENCES reftable [ ( refcolumn ) ] [ MATCH FULL | MATCH PARTIAL | MATCH SIMPLE ]
           [ ON DELETE action ] [ ON UPDATE action ] }
       [ DEFERRABLE | NOT DEFERRABLE ] [ INITIALLY DEFERRED | INITIALLY IMMEDIATE ]

       and table_constraint is:

       [ CONSTRAINT constraint_name ]
       { CHECK ( expression ) |
         UNIQUE ( column_name [, ... ] ) index_parameters |
         PRIMARY KEY ( column_name [, ... ] ) index_parameters |
         EXCLUDE [ USING index_method ] ( exclude_element WITH operator [, ... ] ) index_parameters [ WHERE ( predicate ) ] |
         FOREIGN KEY ( column_name [, ... ] ) REFERENCES reftable [ ( refcolumn [, ... ] ) ]
           [ MATCH FULL | MATCH PARTIAL | MATCH SIMPLE ] [ ON DELETE action ] [ ON UPDATE action ] }
       [ DEFERRABLE | NOT DEFERRABLE ] [ INITIALLY DEFERRED | INITIALLY IMMEDIATE ]

       and like_option is:

       { INCLUDING | EXCLUDING } { DEFAULTS | CONSTRAINTS | INDEXES | STORAGE | COMMENTS | ALL }

       index_parameters in UNIQUE, PRIMARY KEY, and EXCLUDE constraints are:

       [ WITH ( storage_parameter [= value] [, ... ] ) ]
       [ USING INDEX TABLESPACE tablespace ]

       exclude_element in an EXCLUDE constraint is:

       { column | ( expression ) } [ opclass ] [ ASC | DESC ] [ NULLS { FIRST | LAST } ]

DESCRIPTION

       CREATE TABLE will create a new, initially empty table in the current
       database. The table will be owned by the user issuing the command.

       If a schema name is given (for example, CREATE TABLE myschema.mytable
       ...) then the table is created in the specified schema. Otherwise it is
       created in the current schema. Temporary tables exist in a special
       schema, so a schema name cannot be given when creating a temporary
       table. The name of the table must be distinct from the name of any
       other table, sequence, index, view, or foreign table in the same
       schema.

       CREATE TABLE also automatically creates a data type that represents the
       composite type corresponding to one row of the table. Therefore, tables
       cannot have the same name as any existing data type in the same schema.

       The optional constraint clauses specify constraints (tests) that new or
       updated rows must satisfy for an insert or update operation to succeed.
       A constraint is an SQL object that helps define the set of valid values
       in the table in various ways.

       There are two ways to define constraints: table constraints and column
       constraints. A column constraint is defined as part of a column
       definition. A table constraint definition is not tied to a particular
       column, and it can encompass more than one column. Every column
       constraint can also be written as a table constraint; a column
       constraint is only a notational convenience for use when the constraint
       only affects one column.

PARAMETERS

       TEMPORARY or TEMP
           If specified, the table is created as a temporary table. Temporary
           tables are automatically dropped at the end of a session, or
           optionally at the end of the current transaction (see ON COMMIT
           below). Existing permanent tables with the same name are not
           visible to the current session while the temporary table exists,
           unless they are referenced with schema-qualified names. Any indexes
           created on a temporary table are automatically temporary as well.

           The autovacuum daemon cannot access and therefore cannot vacuum or
           analyze temporary tables. For this reason, appropriate vacuum and
           analyze operations should be performed via session SQL commands.
           For example, if a temporary table is going to be used in complex
           queries, it is wise to run ANALYZE on the temporary table after it
           is populated.

           Optionally, GLOBAL or LOCAL can be written before TEMPORARY or
           TEMP. This makes no difference in PostgreSQL, but see
           COMPATIBILITY.

       UNLOGGED
           If specified, the table is created as an unlogged table. Data
           written to unlogged tables is not written to the write-ahead log
           (see Chapter 29, Reliability and the Write-Ahead Log, in the
           documentation), which makes them considerably faster than ordinary
           tables. However, they are not crash-safe: an unlogged table is
           automatically truncated after a crash or unclean shutdown. The
           contents of an unlogged table are also not replicated to standby
           servers. Any indexes created on an unlogged table are automatically
           unlogged as well; however, unlogged GiST indexes are currently not
           supported and cannot be created on an unlogged table.

       IF NOT EXISTS
           Do not throw an error if a relation with the same name already
           exists. A notice is issued in this case. Note that there is no
           guarantee that the existing relation is anything like the one that
           would have been created.

       table_name
           The name (optionally schema-qualified) of the table to be created.

       OF type_name
           Creates a typed table, which takes its structure from the specified
           composite type (name optionally schema-qualified). A typed table is
           tied to its type; for example the table will be dropped if the type
           is dropped (with DROP TYPE ... CASCADE).

           When a typed table is created, then the data types of the columns
           are determined by the underlying composite type and are not
           specified by the CREATE TABLE command. But the CREATE TABLE command
           can add defaults and constraints to the table and can specify
           storage parameters.

       column_name
           The name of a column to be created in the new table.

       data_type
           The data type of the column. This can include array specifiers. For
           more information on the data types supported by PostgreSQL, refer
           to Chapter 8, Data Types, in the documentation.

       COLLATE collation
           The COLLATE clause assigns a collation to the column (which must be
           of a collatable data type). If not specified, the column data
           type's default collation is used.

       INHERITS ( parent_table [, ... ] )
           The optional INHERITS clause specifies a list of tables from which
           the new table automatically inherits all columns.

           Use of INHERITS creates a persistent relationship between the new
           child table and its parent table(s). Schema modifications to the
           parent(s) normally propagate to children as well, and by default
           the data of the child table is included in scans of the parent(s).

           If the same column name exists in more than one parent table, an
           error is reported unless the data types of the columns match in
           each of the parent tables. If there is no conflict, then the
           duplicate columns are merged to form a single column in the new
           table. If the column name list of the new table contains a column
           name that is also inherited, the data type must likewise match the
           inherited column(s), and the column definitions are merged into
           one. If the new table explicitly specifies a default value for the
           column, this default overrides any defaults from inherited
           declarations of the column. Otherwise, any parents that specify
           default values for the column must all specify the same default, or
           an error will be reported.

           CHECK constraints are merged in essentially the same way as
           columns: if multiple parent tables and/or the new table definition
           contain identically-named CHECK constraints, these constraints must
           all have the same check expression, or an error will be reported.
           Constraints having the same name and expression will be merged into
           one copy. Notice that an unnamed CHECK constraint in the new table
           will never be merged, since a unique name will always be chosen for
           it.

           Column STORAGE settings are also copied from parent tables.

       LIKE parent_table [ like_option ... ]
           The LIKE clause specifies a table from which the new table
           automatically copies all column names, their data types, and their
           not-null constraints.

           Unlike INHERITS, the new table and original table are completely
           decoupled after creation is complete. Changes to the original table
           will not be applied to the new table, and it is not possible to
           include data of the new table in scans of the original table.

           Default expressions for the copied column definitions will only be
           copied if INCLUDING DEFAULTS is specified. The default behavior is
           to exclude default expressions, resulting in the copied columns in
           the new table having null defaults.

           Not-null constraints are always copied to the new table.  CHECK
           constraints will only be copied if INCLUDING CONSTRAINTS is
           specified; other types of constraints will never be copied. Also,
           no distinction is made between column constraints and table
           constraints -- when constraints are requested, all check
           constraints are copied.

           Any indexes on the original table will not be created on the new
           table, unless the INCLUDING INDEXES clause is specified.

           STORAGE settings for the copied column definitions will only be
           copied if INCLUDING STORAGE is specified. The default behavior is
           to exclude STORAGE settings, resulting in the copied columns in the
           new table having type-specific default settings. For more on
           STORAGE settings, see Section 55.2, "TOAST", in the documentation.

           Comments for the copied columns, constraints, and indexes will only
           be copied if INCLUDING COMMENTS is specified. The default behavior
           is to exclude comments, resulting in the copied columns and
           constraints in the new table having no comments.

           INCLUDING ALL is an abbreviated form of INCLUDING DEFAULTS
           INCLUDING CONSTRAINTS INCLUDING INDEXES INCLUDING STORAGE INCLUDING
           COMMENTS.

           Note also that unlike INHERITS, columns and constraints copied by
           LIKE are not merged with similarly named columns and constraints.
           If the same name is specified explicitly or in another LIKE clause,
           an error is signalled.

       CONSTRAINT constraint_name
           An optional name for a column or table constraint. If the
           constraint is violated, the constraint name is present in error
           messages, so constraint names like col must be positive can be used
           to communicate helpful constraint information to client
           applications. (Double-quotes are needed to specify constraint names
           that contain spaces.) If a constraint name is not specified, the
           system generates a name.

       NOT NULL
           The column is not allowed to contain null values.

       NULL
           The column is allowed to contain null values. This is the default.

           This clause is only provided for compatibility with non-standard
           SQL databases. Its use is discouraged in new applications.

       CHECK ( expression )
           The CHECK clause specifies an expression producing a Boolean result
           which new or updated rows must satisfy for an insert or update
           operation to succeed. Expressions evaluating to TRUE or UNKNOWN
           succeed. Should any row of an insert or update operation produce a
           FALSE result an error exception is raised and the insert or update
           does not alter the database. A check constraint specified as a
           column constraint should reference that column's value only, while
           an expression appearing in a table constraint can reference
           multiple columns.

           Currently, CHECK expressions cannot contain subqueries nor refer to
           variables other than columns of the current row.

       DEFAULT default_expr
           The DEFAULT clause assigns a default data value for the column
           whose column definition it appears within. The value is any
           variable-free expression (subqueries and cross-references to other
           columns in the current table are not allowed). The data type of the
           default expression must match the data type of the column.

           The default expression will be used in any insert operation that
           does not specify a value for the column. If there is no default for
           a column, then the default is null.

       UNIQUE (column constraint), UNIQUE ( column_name [, ... ] ) (table
       constraint)
           The UNIQUE constraint specifies that a group of one or more columns
           of a table can contain only unique values. The behavior of the
           unique table constraint is the same as that for column constraints,
           with the additional capability to span multiple columns.

           For the purpose of a unique constraint, null values are not
           considered equal.

           Each unique table constraint must name a set of columns that is
           different from the set of columns named by any other unique or
           primary key constraint defined for the table. (Otherwise it would
           just be the same constraint listed twice.)

       PRIMARY KEY (column constraint), PRIMARY KEY ( column_name [, ... ] )
       (table constraint)
           The primary key constraint specifies that a column or columns of a
           table can contain only unique (non-duplicate), nonnull values.
           Technically, PRIMARY KEY is merely a combination of UNIQUE and NOT
           NULL, but identifying a set of columns as primary key also provides
           metadata about the design of the schema, as a primary key implies
           that other tables can rely on this set of columns as a unique
           identifier for rows.

           Only one primary key can be specified for a table, whether as a
           column constraint or a table constraint.

           The primary key constraint should name a set of columns that is
           different from other sets of columns named by any unique constraint
           defined for the same table.

       EXCLUDE [ USING index_method ] ( exclude_element WITH operator [, ... ]
       ) index_parameters [ WHERE ( predicate ) ]
           The EXCLUDE clause defines an exclusion constraint, which
           guarantees that if any two rows are compared on the specified
           column(s) or expression(s) using the specified operator(s), not all
           of these comparisons will return TRUE. If all of the specified
           operators test for equality, this is equivalent to a UNIQUE
           constraint, although an ordinary unique constraint will be faster.
           However, exclusion constraints can specify constraints that are
           more general than simple equality. For example, you can specify a
           constraint that no two rows in the table contain overlapping
           circles (see Section 8.8, "Geometric Types", in the documentation)
           by using the && operator.

           Exclusion constraints are implemented using an index, so each
           specified operator must be associated with an appropriate operator
           class (see Section 11.9, "Operator Classes and Operator Families",
           in the documentation) for the index access method index_method. The
           operators are required to be commutative. Each exclude_element can
           optionally specify an operator class and/or ordering options; these
           are described fully under CREATE INDEX (CREATE_INDEX(7)).

           The access method must support amgettuple (see Chapter 52, Index
           Access Method Interface Definition, in the documentation); at
           present this means GIN cannot be used. Although it's allowed, there
           is little point in using B-tree or hash indexes with an exclusion
           constraint, because this does nothing that an ordinary unique
           constraint doesn't do better. So in practice the access method will
           always be GiST.

           The predicate allows you to specify an exclusion constraint on a
           subset of the table; internally this creates a partial index. Note
           that parentheses are required around the predicate.

       REFERENCES reftable [ ( refcolumn ) ] [ MATCH matchtype ] [ ON DELETE
       action ] [ ON UPDATE action ] (column constraint), FOREIGN KEY ( column
       [, ... ] ) REFERENCES reftable [ ( refcolumn [, ... ] ) ] [ MATCH
       matchtype ] [ ON DELETE action ] [ ON UPDATE action ] (table
       constraint)
           These clauses specify a foreign key constraint, which requires that
           a group of one or more columns of the new table must only contain
           values that match values in the referenced column(s) of some row of
           the referenced table. If refcolumn is omitted, the primary key of
           the reftable is used. The referenced columns must be the columns of
           a non-deferrable unique or primary key constraint in the referenced
           table. Note that foreign key constraints cannot be defined between
           temporary tables and permanent tables.

           A value inserted into the referencing column(s) is matched against
           the values of the referenced table and referenced columns using the
           given match type. There are three match types: MATCH FULL, MATCH
           PARTIAL, and MATCH SIMPLE, which is also the default.  MATCH FULL
           will not allow one column of a multicolumn foreign key to be null
           unless all foreign key columns are null.  MATCH SIMPLE allows some
           foreign key columns to be null while other parts of the foreign key
           are not null.  MATCH PARTIAL is not yet implemented.

           In addition, when the data in the referenced columns is changed,
           certain actions are performed on the data in this table's columns.
           The ON DELETE clause specifies the action to perform when a
           referenced row in the referenced table is being deleted. Likewise,
           the ON UPDATE clause specifies the action to perform when a
           referenced column in the referenced table is being updated to a new
           value. If the row is updated, but the referenced column is not
           actually changed, no action is done. Referential actions other than
           the NO ACTION check cannot be deferred, even if the constraint is
           declared deferrable. There are the following possible actions for
           each clause:

           NO ACTION
               Produce an error indicating that the deletion or update would
               create a foreign key constraint violation. If the constraint is
               deferred, this error will be produced at constraint check time
               if there still exist any referencing rows. This is the default
               action.

           RESTRICT
               Produce an error indicating that the deletion or update would
               create a foreign key constraint violation. This is the same as
               NO ACTION except that the check is not deferrable.

           CASCADE
               Delete any rows referencing the deleted row, or update the
               value of the referencing column to the new value of the
               referenced column, respectively.

           SET NULL
               Set the referencing column(s) to null.

           SET DEFAULT
               Set the referencing column(s) to their default values.

           If the referenced column(s) are changed frequently, it might be
           wise to add an index to the foreign key column so that referential
           actions associated with the foreign key column can be performed
           more efficiently.

       DEFERRABLE, NOT DEFERRABLE
           This controls whether the constraint can be deferred. A constraint
           that is not deferrable will be checked immediately after every
           command. Checking of constraints that are deferrable can be
           postponed until the end of the transaction (using the SET
           CONSTRAINTS (SET_CONSTRAINTS(7)) command).  NOT DEFERRABLE is the
           default. Currently, only UNIQUE, PRIMARY KEY, EXCLUDE, and
           REFERENCES (foreign key) constraints accept this clause.  NOT NULL
           and CHECK constraints are not deferrable.

       INITIALLY IMMEDIATE, INITIALLY DEFERRED
           If a constraint is deferrable, this clause specifies the default
           time to check the constraint. If the constraint is INITIALLY
           IMMEDIATE, it is checked after each statement. This is the default.
           If the constraint is INITIALLY DEFERRED, it is checked only at the
           end of the transaction. The constraint check time can be altered
           with the SET CONSTRAINTS (SET_CONSTRAINTS(7)) command.

       WITH ( storage_parameter [= value] [, ... ] )
           This clause specifies optional storage parameters for a table or
           index; see Storage Parameters for more information. The WITH clause
           for a table can also include OIDS=TRUE (or just OIDS) to specify
           that rows of the new table should have OIDs (object identifiers)
           assigned to them, or OIDS=FALSE to specify that the rows should not
           have OIDs. If OIDS is not specified, the default setting depends
           upon the default_with_oids configuration parameter. (If the new
           table inherits from any tables that have OIDs, then OIDS=TRUE is
           forced even if the command says OIDS=FALSE.)

           If OIDS=FALSE is specified or implied, the new table does not store
           OIDs and no OID will be assigned for a row inserted into it. This
           is generally considered worthwhile, since it will reduce OID
           consumption and thereby postpone the wraparound of the 32-bit OID
           counter. Once the counter wraps around, OIDs can no longer be
           assumed to be unique, which makes them considerably less useful. In
           addition, excluding OIDs from a table reduces the space required to
           store the table on disk by 4 bytes per row (on most machines),
           slightly improving performance.

           To remove OIDs from a table after it has been created, use ALTER
           TABLE (ALTER_TABLE(7)).

       WITH OIDS, WITHOUT OIDS
           These are obsolescent syntaxes equivalent to WITH (OIDS) and WITH
           (OIDS=FALSE), respectively. If you wish to give both an OIDS
           setting and storage parameters, you must use the WITH ( ... )
           syntax; see above.

       ON COMMIT
           The behavior of temporary tables at the end of a transaction block
           can be controlled using ON COMMIT. The three options are:

           PRESERVE ROWS
               No special action is taken at the ends of transactions. This is
               the default behavior.

           DELETE ROWS
               All rows in the temporary table will be deleted at the end of
               each transaction block. Essentially, an automatic TRUNCATE(7)
               is done at each commit.

           DROP
               The temporary table will be dropped at the end of the current
               transaction block.

       TABLESPACE tablespace
           The tablespace is the name of the tablespace in which the new table
           is to be created. If not specified, default_tablespace is
           consulted, or temp_tablespaces if the table is temporary.

       USING INDEX TABLESPACE tablespace
           This clause allows selection of the tablespace in which the index
           associated with a UNIQUE, PRIMARY KEY, or EXCLUDE constraint will
           be created. If not specified, default_tablespace is consulted, or
           temp_tablespaces if the table is temporary.

   Storage Parameters
       The WITH clause can specify storage parameters for tables, and for
       indexes associated with a UNIQUE, PRIMARY KEY, or EXCLUDE constraint.
       Storage parameters for indexes are documented in CREATE INDEX
       (CREATE_INDEX(7)). The storage parameters currently available for
       tables are listed below. For each parameter, unless noted, there is an
       additional parameter with the same name prefixed with toast., which can
       be used to control the behavior of the table's secondary TOAST table,
       if any (see Section 55.2, "TOAST", in the documentation for more
       information about TOAST). Note that the TOAST table inherits the
       autovacuum_* values from its parent table, if there are no
       toast.autovacuum_* settings set.

       fillfactor (integer)
           The fillfactor for a table is a percentage between 10 and 100. 100
           (complete packing) is the default. When a smaller fillfactor is
           specified, INSERT operations pack table pages only to the indicated
           percentage; the remaining space on each page is reserved for
           updating rows on that page. This gives UPDATE a chance to place the
           updated copy of a row on the same page as the original, which is
           more efficient than placing it on a different page. For a table
           whose entries are never updated, complete packing is the best
           choice, but in heavily updated tables smaller fillfactors are
           appropriate. This parameter cannot be set for TOAST tables.

       autovacuum_enabled, toast.autovacuum_enabled (boolean)
           Enables or disables the autovacuum daemon on a particular table. If
           true, the autovacuum daemon will initiate a VACUUM operation on a
           particular table when the number of updated or deleted tuples
           exceeds autovacuum_vacuum_threshold plus
           autovacuum_vacuum_scale_factor times the number of live tuples
           currently estimated to be in the relation. Similarly, it will
           initiate an ANALYZE operation when the number of inserted, updated
           or deleted tuples exceeds autovacuum_analyze_threshold plus
           autovacuum_analyze_scale_factor times the number of live tuples
           currently estimated to be in the relation. If false, this table
           will not be autovacuumed, except to prevent transaction Id
           wraparound. See Section 23.1.4, "Preventing Transaction ID
           Wraparound Failures", in the documentation for more about
           wraparound prevention. Observe that this variable inherits its
           value from the autovacuum setting.

       autovacuum_vacuum_threshold, toast.autovacuum_vacuum_threshold
       (integer)
           Minimum number of updated or deleted tuples before initiate a
           VACUUM operation on a particular table.

       autovacuum_vacuum_scale_factor, toast.autovacuum_vacuum_scale_factor
       (float4)
           Multiplier for reltuples to add to autovacuum_vacuum_threshold.

       autovacuum_analyze_threshold (integer)
           Minimum number of inserted, updated, or deleted tuples before
           initiate an ANALYZE operation on a particular table.

       autovacuum_analyze_scale_factor (float4)
           Multiplier for reltuples to add to autovacuum_analyze_threshold.

       autovacuum_vacuum_cost_delay, toast.autovacuum_vacuum_cost_delay
       (integer)
           Custom autovacuum_vacuum_cost_delay parameter.

       autovacuum_vacuum_cost_limit, toast.autovacuum_vacuum_cost_limit
       (integer)
           Custom autovacuum_vacuum_cost_limit parameter.

       autovacuum_freeze_min_age, toast.autovacuum_freeze_min_age (integer)
           Custom vacuum_freeze_min_age parameter. Note that autovacuum will
           ignore attempts to set a per-table autovacuum_freeze_min_age larger
           than the half system-wide autovacuum_freeze_max_age setting.

       autovacuum_freeze_max_age, toast.autovacuum_freeze_max_age (integer)
           Custom autovacuum_freeze_max_age parameter. Note that autovacuum
           will ignore attempts to set a per-table autovacuum_freeze_max_age
           larger than the system-wide setting (it can only be set smaller).
           Note that while you can set autovacuum_freeze_max_age very small,
           or even zero, this is usually unwise since it will force frequent
           vacuuming.

       autovacuum_freeze_table_age, toast.autovacuum_freeze_table_age
       (integer)
           Custom vacuum_freeze_table_age parameter.

NOTES

       Using OIDs in new applications is not recommended: where possible,
       using a SERIAL or other sequence generator as the table's primary key
       is preferred. However, if your application does make use of OIDs to
       identify specific rows of a table, it is recommended to create a unique
       constraint on the oid column of that table, to ensure that OIDs in the
       table will indeed uniquely identify rows even after counter wraparound.
       Avoid assuming that OIDs are unique across tables; if you need a
       database-wide unique identifier, use the combination of tableoid and
       row OID for the purpose.

           Tip
           The use of OIDS=FALSE is not recommended for tables with no primary
           key, since without either an OID or a unique data key, it is
           difficult to identify specific rows.

       PostgreSQL automatically creates an index for each unique constraint
       and primary key constraint to enforce uniqueness. Thus, it is not
       necessary to create an index explicitly for primary key columns. (See
       CREATE INDEX (CREATE_INDEX(7)) for more information.)

       Unique constraints and primary keys are not inherited in the current
       implementation. This makes the combination of inheritance and unique
       constraints rather dysfunctional.

       A table cannot have more than 1600 columns. (In practice, the effective
       limit is usually lower because of tuple-length constraints.)

EXAMPLES

       Create table films and table distributors:

           CREATE TABLE films (
               code        char(5) CONSTRAINT firstkey PRIMARY KEY,
               title       varchar(40) NOT NULL,
               did         integer NOT NULL,
               date_prod   date,
               kind        varchar(10),
               len         interval hour to minute
           );

           CREATE TABLE distributors (
                did    integer PRIMARY KEY DEFAULT nextval('serial'),
                name   varchar(40) NOT NULL CHECK (name <> '')
           );

       Create a table with a 2-dimensional array:

           CREATE TABLE array_int (
               vector  int[][]
           );

       Define a unique table constraint for the table films. Unique table
       constraints can be defined on one or more columns of the table:

           CREATE TABLE films (
               code        char(5),
               title       varchar(40),
               did         integer,
               date_prod   date,
               kind        varchar(10),
               len         interval hour to minute,
               CONSTRAINT production UNIQUE(date_prod)
           );

       Define a check column constraint:

           CREATE TABLE distributors (
               did     integer CHECK (did > 100),
               name    varchar(40)
           );

       Define a check table constraint:

           CREATE TABLE distributors (
               did     integer,
               name    varchar(40)
               CONSTRAINT con1 CHECK (did > 100 AND name <> '')
           );

       Define a primary key table constraint for the table films:

           CREATE TABLE films (
               code        char(5),
               title       varchar(40),
               did         integer,
               date_prod   date,
               kind        varchar(10),
               len         interval hour to minute,
               CONSTRAINT code_title PRIMARY KEY(code,title)
           );

       Define a primary key constraint for table distributors. The following
       two examples are equivalent, the first using the table constraint
       syntax, the second the column constraint syntax:

           CREATE TABLE distributors (
               did     integer,
               name    varchar(40),
               PRIMARY KEY(did)
           );

           CREATE TABLE distributors (
               did     integer PRIMARY KEY,
               name    varchar(40)
           );

       Assign a literal constant default value for the column name, arrange
       for the default value of column did to be generated by selecting the
       next value of a sequence object, and make the default value of modtime
       be the time at which the row is inserted:

           CREATE TABLE distributors (
               name      varchar(40) DEFAULT 'Luso Films',
               did       integer DEFAULT nextval('distributors_serial'),
               modtime   timestamp DEFAULT current_timestamp
           );

       Define two NOT NULL column constraints on the table distributors, one
       of which is explicitly given a name:

           CREATE TABLE distributors (
               did     integer CONSTRAINT no_null NOT NULL,
               name    varchar(40) NOT NULL
           );

       Define a unique constraint for the name column:

           CREATE TABLE distributors (
               did     integer,
               name    varchar(40) UNIQUE
           );

       The same, specified as a table constraint:

           CREATE TABLE distributors (
               did     integer,
               name    varchar(40),
               UNIQUE(name)
           );

       Create the same table, specifying 70% fill factor for both the table
       and its unique index:

           CREATE TABLE distributors (
               did     integer,
               name    varchar(40),
               UNIQUE(name) WITH (fillfactor=70)
           )
           WITH (fillfactor=70);

       Create table circles with an exclusion constraint that prevents any two
       circles from overlapping:

           CREATE TABLE circles (
               c circle,
               EXCLUDE USING gist (c WITH &&)
           );

       Create table cinemas in tablespace diskvol1:

           CREATE TABLE cinemas (
                   id serial,
                   name text,
                   location text
           ) TABLESPACE diskvol1;

       Create a composite type and a typed table:

           CREATE TYPE employee_type AS (name text, salary numeric);

           CREATE TABLE employees OF employee_type (
               PRIMARY KEY (name),
               salary WITH OPTIONS DEFAULT 1000
           );

COMPATIBILITY

       The CREATE TABLE command conforms to the SQL standard, with exceptions
       listed below.

   Temporary Tables
       Although the syntax of CREATE TEMPORARY TABLE resembles that of the SQL
       standard, the effect is not the same. In the standard, temporary tables
       are defined just once and automatically exist (starting with empty
       contents) in every session that needs them.  PostgreSQL instead
       requires each session to issue its own CREATE TEMPORARY TABLE command
       for each temporary table to be used. This allows different sessions to
       use the same temporary table name for different purposes, whereas the
       standard's approach constrains all instances of a given temporary table
       name to have the same table structure.

       The standard's definition of the behavior of temporary tables is widely
       ignored.  PostgreSQL's behavior on this point is similar to that of
       several other SQL databases.

       The standard's distinction between global and local temporary tables is
       not in PostgreSQL, since that distinction depends on the concept of
       modules, which PostgreSQL does not have. For compatibility's sake,
       PostgreSQL will accept the GLOBAL and LOCAL keywords in a temporary
       table declaration, but they have no effect.

       The ON COMMIT clause for temporary tables also resembles the SQL
       standard, but has some differences. If the ON COMMIT clause is omitted,
       SQL specifies that the default behavior is ON COMMIT DELETE ROWS.
       However, the default behavior in PostgreSQL is ON COMMIT PRESERVE ROWS.
       The ON COMMIT DROP option does not exist in SQL.

   Non-deferred Uniqueness Constraints
       When a UNIQUE or PRIMARY KEY constraint is not deferrable, PostgreSQL
       checks for uniqueness immediately whenever a row is inserted or
       modified. The SQL standard says that uniqueness should be enforced only
       at the end of the statement; this makes a difference when, for example,
       a single command updates multiple key values. To obtain
       standard-compliant behavior, declare the constraint as DEFERRABLE but
       not deferred (i.e., INITIALLY IMMEDIATE). Be aware that this can be
       significantly slower than immediate uniqueness checking.

   Column Check Constraints
       The SQL standard says that CHECK column constraints can only refer to
       the column they apply to; only CHECK table constraints can refer to
       multiple columns.  PostgreSQL does not enforce this restriction; it
       treats column and table check constraints alike.

   EXCLUDE Constraint
       The EXCLUDE constraint type is a PostgreSQL extension.

   NULL "Constraint"
       The NULL "constraint" (actually a non-constraint) is a PostgreSQL
       extension to the SQL standard that is included for compatibility with
       some other database systems (and for symmetry with the NOT NULL
       constraint). Since it is the default for any column, its presence is
       simply noise.

   Inheritance
       Multiple inheritance via the INHERITS clause is a PostgreSQL language
       extension. SQL:1999 and later define single inheritance using a
       different syntax and different semantics. SQL:1999-style inheritance is
       not yet supported by PostgreSQL.

   Zero-column Tables
       PostgreSQL allows a table of no columns to be created (for example,
       CREATE TABLE foo();). This is an extension from the SQL standard, which
       does not allow zero-column tables. Zero-column tables are not in
       themselves very useful, but disallowing them creates odd special cases
       for ALTER TABLE DROP COLUMN, so it seems cleaner to ignore this spec
       restriction.

   WITH Clause
       The WITH clause is a PostgreSQL extension; neither storage parameters
       nor OIDs are in the standard.

   Tablespaces
       The PostgreSQL concept of tablespaces is not part of the standard.
       Hence, the clauses TABLESPACE and USING INDEX TABLESPACE are
       extensions.

   Typed Tables
       Typed tables implement a subset of the SQL standard. According to the
       standard, a typed table has columns corresponding to the underlying
       composite type as well as one other column that is the
       "self-referencing column". PostgreSQL does not support these
       self-referencing columns explicitly, but the same effect can be had
       using the OID feature.

SEE ALSO

       ALTER TABLE (ALTER_TABLE(7)), DROP TABLE (DROP_TABLE(7)), CREATE
       TABLESPACE (CREATE_TABLESPACE(7)), CREATE TYPE (CREATE_TYPE(7))