Provided by: postgresql-client-8.4_8.4.11-1_i386 bug

NAME

       CREATE TABLE - define a new table

SYNOPSIS

       CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } ] TABLE table_name ( [
         { column_name data_type [ DEFAULT default_expr ] [ column_constraint [ ... ] ]
           | table_constraint
           | LIKE parent_table [ { INCLUDING | EXCLUDING } { DEFAULTS | CONSTRAINTS | INDEXES } ] ... }
           [, ... ]
       ] )
       [ INHERITS ( parent_table [, ... ] ) ]
       [ 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 |
         UNIQUE index_parameters |
         PRIMARY KEY index_parameters |
         CHECK ( expression ) |
         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 ]
       { UNIQUE ( column_name [, ... ] ) index_parameters |
         PRIMARY KEY ( column_name [, ... ] ) index_parameters |
         CHECK ( expression ) |
         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 ]

       index_parameters in UNIQUE and PRIMARY KEY constraints are:

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

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, or view 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.

              Optionally,  GLOBAL  or LOCAL can be written before TEMPORARY or
              TEMP.   This  makes  no  difference  in  PostgreSQL,   but   see
              Compatibility [create_table(7)].

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

       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 in the documentation.

       DEFAULT
              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.

       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.

       LIKE parent_table [ { INCLUDING | EXCLUDING } { DEFAULTS |  CONSTRAINTS
       | INDEXES } ]
              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.

              Note also that unlike INHERITS, copied columns  and  constraints
              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.

       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.

       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.

       REFERENCES  reftable  [ ( refcolumn ) ] [ MATCH matchtype ] [ ON DELETE
       action ] [ ON UPDATE action ] (column constraint)

       FOREIGN KEY ( column [, ... ] )
              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  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. Only foreign key constraints currently accept  this
              clause. All other constraint types 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  [create_table(7)]   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 [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 or PRIMARY KEY 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 or PRIMARY KEY 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  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 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 cinemas in tablespace diskvol1:

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

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.

   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.

   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.

SEE ALSO

       ALTER  TABLE  [alter_table(7)],  DROP  TABLE  [drop_table(7)],   CREATE
       TABLESPACE [create_tablespace(7)]