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CREATE TABLE(7)		PostgreSQL 9.2.5 Documentation	       CREATE TABLE(7)

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 source_table [ like_option ... ] }
	   [, ... ]
       ] )
       [ INHERITS ( parent_table [, ... ] ) ]
       [ WITH ( storage_parameter [= value] [, ... ] ) | WITH OIDS | WITHOUT OIDS ]
       [ ON COMMIT { PRESERVE ROWS | DELETE ROWS | DROP } ]
       [ TABLESPACE tablespace_name ]

       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_name ]

       where column_constraint is:

       [ CONSTRAINT constraint_name ]
       { NOT NULL |
	 NULL |
	 CHECK ( expression ) [ NO INHERIT ] |
	 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 ) [ NO INHERIT ] |
	 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_name ]

       exclude_element in an EXCLUDE constraint is:

       { column_name | ( 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.

       To be able to create a table, you must have USAGE privilege on all
       column types or the type in the OF clause, respectively.

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 presently makes no difference in PostgreSQL and is
	   deprecated; 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. A constraint marked NO INHERIT in a parent will not be
	   considered. 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 source_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 56.2, “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.

	   The LIKE clause can also be used to copy columns from views,
	   foreign tables, or composite types. Inapplicable options (e.g.,
	   INCLUDING INDEXES from a view) are ignored.

       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 ) [ NO INHERIT ]
	   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.

	   A constraint marked with NO INHERIT will not propagate to child
	   tables.

       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 or SP-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_name [, ... ] ) 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_name
	   The tablespace_name 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_name
	   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 56.2, “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 23.1.5, “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 SQL standard also distinguishes between global and local temporary
       tables, where a local temporary table has a separate set of contents
       for each SQL module within each session, though its definition is still
       shared across sessions. Since PostgreSQL does not support SQL modules,
       this distinction is not relevant in PostgreSQL.

       For compatibility's sake, PostgreSQL will accept the GLOBAL and LOCAL
       keywords in a temporary table declaration, but they currently have no
       effect. Use of these keywords is discouraged, since future versions of
       PostgreSQL might adopt a more standard-compliant interpretation of
       their meaning.

       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))

PostgreSQL 9.2.5		  2013-10-08		       CREATE TABLE(7)
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