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pg_class

pg_class

select relname from pg_class;
select * from pg_class where relname like 'pg_class_%'

Структура и индексы таблицы pg_class

=# \d pg_class
      Table "pg_catalog.pg_class"
     Column     |   Type    | Modifiers 
----------------+-----------+-----------
 relname        | name      | not null
 relnamespace   | oid       | not null
 reltype        | oid       | not null
 relowner       | oid       | not null
 relam          | oid       | not null
 relfilenode    | oid       | not null
 reltablespace  | oid       | not null
 relpages       | integer   | not null
 reltuples      | real      | not null
 reltoastrelid  | oid       | not null
 reltoastidxid  | oid       | not null
 relhasindex    | boolean   | not null
 relisshared    | boolean   | not null
 relistemp      | boolean   | not null
 relkind        | "char"    | not null
 relnatts       | smallint  | not null
 relchecks      | smallint  | not null
 relhasoids     | boolean   | not null
 relhaspkey     | boolean   | not null
 relhasrules    | boolean   | not null
 relhastriggers | boolean   | not null
 relhassubclass | boolean   | not null
 relfrozenxid   | xid       | not null
 relacl         | aclitem[] | 
 reloptions     | text[]    | 
Indexes:
    "pg_class_oid_index" UNIQUE, btree (oid)
    "pg_class_relname_nsp_index" UNIQUE, btree (relname, relnamespace)
Name Type References Description
relname name Name of the table, index, view, etc.
relnamespace oid pg_namespace.oid The OID of the namespace that contains this relation
reltype oid pg_type.oid The OID of the data type that corresponds to this table's row type, if any (zero for indexes, which have no pg_type entry)
relowner oid pg_authid.oid Owner of the relation
relam oid pg_am.oid If this is an index, the access method used (B-tree, hash, etc.)
relfilenode oid Name of the on-disk file of this relation; 0 if noneИмя файла на HDD; 0 если файл не существует
reltablespace oid pg_tablespace.oid The tablespace in which this relation is stored. If zero, the database's default tablespace is implied. (Not meaningful if the relation has no on-disk file.)
relpages int4 Size of the on-disk representation of this table in pages (of size BLCKSZ). This is only an estimate used by the planner. It is updated by VACUUM, ANALYZE, and a few DDL commands such as CREATE INDEX
reltuples float4 Number of rows in the table. This is only an estimate used by the planner. It is updated by VACUUM, ANALYZE, and a few DDL commands such as CREATE INDEX
reltoastrelid oid pg_class.oid OID of the TOAST table associated with this table, 0 if none. The TOAST table stores large attributes "out of line" in a secondary table
reltoastidxid oid pg_class.oid For a TOAST table, the OID of its index. 0 if not a TOAST table
relhasindex bool True if this is a table and it has (or recently had) any indexes. This is set by CREATE INDEX, but not cleared immediately by DROP INDEX. VACUUM clears relhasindex if it finds the table has no indexes
relisshared bool True if this table is shared across all databases in the cluster. Only certain system catalogs (such as pg_database) are shared
relistemp bool True if this table is a temporary relation. If so, only the creating session can safely access its contents
relkind char r = ordinary table, i = index, S = sequence, v = view, c = composite type, t = TOAST table
relnatts int2 Number of user columns in the relation (system columns not counted). There must be this many corresponding entries in pg_attribute. See also pg_attribute.attnum
relchecks int2 Number of CHECK constraints on the table; see pg_constraint catalog
relhasoids bool True if we generate an OID for each row of the relation
relhaspkey bool True if the table has (or once had) a primary key
relhasrules bool True if table has (or once had) rules; see pg_rewrite catalog
relhastriggers bool True if table has (or once had) triggers; see pg_trigger catalog
relhassubclass bool True if table has (or once had) any inheritance children
relfrozenxid xid All transaction IDs before this one have been replaced with a permanent ("frozen") transaction ID in this table. This is used to track whether the table needs to be vacuumed in order to prevent transaction ID wraparound or to allow pg_clog to be shrunk. Zero (InvalidTransactionId) if the relation is not a table
relacl aclitem[] Access privileges; see GRANT and REVOKE for detailsПривилегии доступа.
reloptions text[] Access-method-specific options, as "keyword=value" strings

pg_class.txt · Последние изменения: 2012/05/30 12:59 (внешнее изменение)