{"Entry":{"collection":"catalog","key":"pg_class","name":"pg_class","aliases":[],"metadata":{"changed_in":["8.0","8.1","8.2","8.4","9.0","9.1","9.2","9.3","9.4","9.5","10","11","12","18"],"changes":[{"added":["reltablespace"],"attributes":[],"description_changed":true,"descriptions":[{"from":"Access privileges; see the descriptions of GRANT and REVOKE for details.","name":"relacl","to":"Access privileges; see GRANT and REVOKE for details."},{"from":"Table has rules; see pg_rewrite catalog","name":"relhasrules","to":"True if table has rules; see pg_rewrite catalog."},{"from":"At least one table inherits from this one","name":"relhassubclass","to":"True if table has (or once had) any inheritance children."},{"from":"Size of the on-disk representation of this table in pages (size BLCKSZ). This is only an estimate used by the planner. It is updated by VACUUM, ANALYZE, and CREATE INDEX.","name":"relpages","to":"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."},{"from":"Number of rows in the table. This is only an estimate used by the planner. It is updated by VACUUM, ANALYZE, and CREATE INDEX.","name":"reltuples","to":"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."},{"from":"The OID of the data type that corresponds to this table, if any (zero for indexes, which have no pg_type entry)","name":"reltype","to":"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)"}],"from":"7.4","listing":[],"order":false,"removed":[],"status":"changed","to":"8.0","types":[],"unlisted":[]},{"added":[],"attributes":[],"description_changed":false,"descriptions":[],"from":"8.0","listing":[],"order":false,"removed":[],"status":"changed","to":"8.1","types":[{"from":"int4","name":"relowner","to":"oid"}],"unlisted":[]},{"added":["relfrozenxid","reloptions"],"attributes":[],"description_changed":true,"descriptions":[{"from":"Access privileges; see GRANT and REVOKE for details.","name":"relacl","to":"Access privileges; see GRANT and REVOKE for details"},{"from":"unused (not the number of foreign keys on the table)","name":"relfkeys","to":"Unused (not the number of foreign keys on the table)"},{"from":"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.","name":"relhasindex","to":"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"},{"from":"True if we generate an OID for each row of the relation.","name":"relhasoids","to":"True if we generate an OID for each row of the relation"},{"from":"True if the table has (or once had) a primary key.","name":"relhaspkey","to":"True if the table has (or once had) a primary key"},{"from":"True if table has rules; see pg_rewrite catalog.","name":"relhasrules","to":"True if table has rules; see pg_rewrite catalog"},{"from":"True if table has (or once had) any inheritance children.","name":"relhassubclass","to":"True if table has (or once had) any inheritance children"},{"from":"True if this table is shared across all databases in the cluster. Only certain system catalogs (such as pg_database) are shared.","name":"relisshared","to":"True if this table is shared across all databases in the cluster. Only certain system catalogs (such as pg_database) are shared"},{"from":"r = ordinary table, i = index, S = sequence, v = view, c = composite type, s = special, t = TOAST table","name":"relkind","to":"r = ordinary table, i = index, S = sequence, v = view, c = composite type, t = TOAST table"},{"from":"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.","name":"relnatts","to":"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"},{"from":"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.","name":"relpages","to":"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"},{"from":"unused","name":"relrefs","to":"Unused"},{"from":"For a TOAST table, the OID of its index. 0 if not a TOAST table.","name":"reltoastidxid","to":"For a TOAST table, the OID of its index. 0 if not a TOAST table"},{"from":"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.","name":"reltoastrelid","to":"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"},{"from":"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.","name":"reltuples","to":"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"},{"from":"unused (not the number of unique keys)","name":"relukeys","to":"Unused (not the number of unique keys)"}],"from":"8.1","listing":[],"order":false,"removed":[],"status":"changed","to":"8.2","types":[],"unlisted":[]},{"added":["relistemp","relhastriggers"],"attributes":[],"description_changed":false,"descriptions":[{"from":"Number of check constraints on the table; see pg_constraint catalog","name":"relchecks","to":"Number of CHECK constraints on the table; see pg_constraint catalog"},{"from":"True if table has rules; see pg_rewrite catalog","name":"relhasrules","to":"True if table has (or once had) rules; see pg_rewrite catalog"}],"from":"8.3","listing":[],"order":false,"removed":["reltriggers","relukeys","relfkeys","relrefs"],"status":"changed","to":"8.4","types":[],"unlisted":[]},{"added":["reloftype","relhasexclusion"],"attributes":[],"description_changed":false,"descriptions":[{"from":"Name of the on-disk file of this relation; 0 if none","name":"relfilenode","to":"Name of the on-disk file of this relation; zero means this is a \"mapped\" relation whose disk file name is determined by low-level state"},{"from":"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","name":"relfrozenxid","to":"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."},{"from":"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","name":"relhasindex","to":"True if this is a table and it has (or recently had) any indexes"},{"from":"True if this table is shared across all databases in the cluster. Only certain system catalogs (such as pg_database) are shared","name":"relisshared","to":"True if this table is shared across all databases in the cluster. Only certain system catalogs (such as pg_database) are shared."},{"from":"True if this table is a temporary relation. If so, only the creating session can safely access its contents","name":"relistemp","to":"True if this table is a temporary relation. If so, only the creating session can safely access its contents."},{"from":"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","name":"relnatts","to":"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."},{"from":"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","name":"relpages","to":"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."},{"from":"For a TOAST table, the OID of its index. 0 if not a TOAST table","name":"reltoastidxid","to":"For a TOAST table, the OID of its index. 0 if not a TOAST table."},{"from":"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","name":"reltoastrelid","to":"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."},{"from":"Number of rows in the table. This is only an estimate used by the planner. 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It is updated by VACUUM, ANALYZE, and a few DDL commands such as CREATE INDEX."}],"from":"8.4","listing":[],"order":false,"removed":[],"status":"changed","to":"9.0","types":[],"unlisted":[]},{"added":["relpersistence"],"attributes":[],"description_changed":false,"descriptions":[{"from":"r = ordinary table, i = index, S = sequence, v = view, c = composite type, t = TOAST table","name":"relkind","to":"r = ordinary table, i = index, S = sequence, v = view, c = composite type, t = TOAST table, f = foreign table"}],"from":"9.0","listing":[],"order":false,"removed":["relistemp","relhasexclusion"],"status":"changed","to":"9.1","types":[],"unlisted":[]},{"added":["relallvisible"],"attributes":[],"description_changed":false,"descriptions":[],"from":"9.1","listing":[],"order":false,"removed":[],"status":"changed","to":"9.2","types":[],"unlisted":[]},{"added":["relispopulated","relminmxid"],"attributes":[],"description_changed":true,"descriptions":[{"from":"r = ordinary table, i = index, S = sequence, v = view, c = composite type, t = TOAST table, f = foreign table","name":"relkind","to":"r = ordinary table, i = index, S = sequence, v = view, m = materialized view, c = composite type, t = TOAST table, f = foreign table"}],"from":"9.2","listing":[],"order":false,"removed":[],"status":"changed","to":"9.3","types":[],"unlisted":[]},{"added":["relreplident"],"attributes":[],"description_changed":false,"descriptions":[],"from":"9.3","listing":[],"order":false,"removed":["reltoastidxid"],"status":"changed","to":"9.4","types":[],"unlisted":[]},{"added":["relrowsecurity","relforcerowsecurity"],"attributes":[],"description_changed":false,"descriptions":[{"from":"Columns used to form \"replica identity\" for rows: d = default (primary key, if any), n = nothing, f = all columns i = index with indisreplident set, or default","name":"relreplident","to":"Columns used to form \"replica identity\" for rows: d = default (primary key, if any), n = nothing, f = all columns, i = index with indisreplident set (same as nothing if the index used has been dropped)"}],"from":"9.4","listing":[],"order":false,"removed":[],"status":"changed","to":"9.5","types":[],"unlisted":[]},{"added":["relispartition","relpartbound"],"attributes":[],"description_changed":true,"descriptions":[{"from":"Name of the on-disk file of this relation; zero means this is a \"mapped\" relation whose disk file name is determined by low-level state","name":"relfilenode","to":"Name of the on-disk file of this relation; zero means this is a “mapped” relation whose disk file name is determined by low-level state"},{"from":"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.","name":"relfrozenxid","to":"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_xact to be shrunk. Zero (InvalidTransactionId) if the relation is not a table."},{"from":"r = ordinary table, i = index, S = sequence, v = view, m = materialized view, c = composite type, t = TOAST table, f = foreign table","name":"relkind","to":"r = ordinary table, i = index, S = sequence, t = TOAST table, v = view, m = materialized view, c = composite type, f = foreign table, p = partitioned table"},{"from":"Access-method-specific options, as \"keyword=value\" strings","name":"reloptions","to":"Access-method-specific options, as “keyword=value” strings"},{"from":"Columns used to form \"replica identity\" for rows: d = default (primary key, if any), n = nothing, f = all columns, i = index with indisreplident set (same as nothing if the index used has been dropped)","name":"relreplident","to":"Columns used to form “replica identity” for rows: d = default (primary key, if any), n = nothing, f = all columns, i = index with indisreplident set (same as nothing if the index used has been dropped)"},{"from":"OID of the TOAST table associated with this table, 0 if none. 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It is updated by VACUUM, ANALYZE, and a few DDL commands such as CREATE INDEX."}],"from":"10","listing":[],"order":false,"removed":["relhaspkey"],"status":"changed","to":"11","types":[],"unlisted":[]},{"added":[],"attributes":[{"attribute":"hidden","from":true,"name":"oid","to":false}],"description_changed":false,"descriptions":[{"from":"Access privileges; see GRANT and REVOKE for details","name":"relacl","to":"Access privileges; see Section 5.7 for details"},{"from":"If this is an index, the access method used (B-tree, hash, etc.)","name":"relam","to":"If this is a table or an index, the access method used (heap, B-tree, hash, etc.)"},{"from":"True if table has (or once had) any inheritance children","name":"relhassubclass","to":"True if table or index has (or once had) any inheritance children"},{"from":"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.)","name":"reltablespace","to":"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, except for partitioned tables, where this is the tablespace in which partitions will be created when one is not specified in the creation command."}],"from":"11","listing":[],"order":false,"removed":["relhasoids"],"status":"changed","to":"12","types":[],"unlisted":[]},{"added":[],"attributes":[],"description_changed":false,"descriptions":[{"from":"If this is a table or an index, the access method used (heap, B-tree, hash, etc.)","name":"relam","to":"If this is a table or an index, the access method used (heap, B-tree, hash, etc.); otherwise zero (zero occurs for sequences, as well as relations without storage, such as views)"},{"from":"True if row level security (when enabled) will also apply to table owner; see pg_policy catalog","name":"relforcerowsecurity","to":"True if row-level security (when enabled) will also apply to table owner; see pg_policy catalog"},{"from":"For typed tables, the OID of the underlying composite type, zero for all other relations","name":"reloftype","to":"For typed tables, the OID of the underlying composite type; zero for all other relations"},{"from":"For new relations being written during a DDL operation that requires a table rewrite, this contains the OID of the original relation; otherwise 0. That state is only visible internally; this field should never contain anything other than 0 for a user-visible relation.","name":"relrewrite","to":"For new relations being written during a DDL operation that requires a table rewrite, this contains the OID of the original relation; otherwise zero. That state is only visible internally; this field should never contain anything other than zero for a user-visible relation."},{"from":"True if table has row level security enabled; see pg_policy catalog","name":"relrowsecurity","to":"True if table has row-level security enabled; see pg_policy catalog"},{"from":"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.","name":"reltoastrelid","to":"OID of the TOAST table associated with this table, zero if none. The TOAST table stores large attributes “out of line” in a secondary table."},{"from":"Number of live 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.","name":"reltuples","to":"Number of live 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. If the table has never yet been vacuumed or analyzed, reltuples contains -1 indicating that the row count is unknown."},{"from":"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)","name":"reltype","to":"The OID of the data type that corresponds to this table's row type, if any; zero for indexes, sequences, and toast tables, which have no pg_type entry"}],"from":"13","listing":[],"order":false,"removed":[],"status":"reworded","to":"14","types":[],"unlisted":[]},{"added":[],"attributes":[],"description_changed":false,"descriptions":[{"from":"True if table or index has (or once had) any inheritance children","name":"relhassubclass","to":"True if table or index has (or once had) any inheritance children or partitions"},{"from":"p = permanent table, u = unlogged table, t = temporary table","name":"relpersistence","to":"p = permanent table/sequence, u = unlogged table/sequence, t = temporary table/sequence"}],"from":"14","listing":[],"order":false,"removed":[],"status":"reworded","to":"15","types":[],"unlisted":[]},{"added":[],"attributes":[],"description_changed":false,"descriptions":[{"from":"Access privileges; see Section 5.7 for details","name":"relacl","to":"Access privileges; see Section 5.8 for details"},{"from":"If this is a table or an index, the access method used (heap, B-tree, hash, etc.); otherwise zero (zero occurs for sequences, as well as relations without storage, such as views)","name":"relam","to":"The access method used to access this table or index. Not meaningful if the relation is a sequence or has no on-disk file, except for partitioned tables, where, if set, it takes precedence over default_table_access_method when determining the access method to use for partitions created when one is not specified in the creation command."}],"from":"16","listing":[],"order":false,"removed":[],"status":"reworded","to":"17","types":[],"unlisted":[]},{"added":["relallfrozen"],"attributes":[],"description_changed":false,"descriptions":[],"from":"17","listing":[],"order":false,"removed":[],"status":"changed","to":"18","types":[],"unlisted":[]},{"added":[],"attributes":[],"description_changed":false,"descriptions":[{"from":"Access privileges; see Section 5.8 for details","name":"relacl","to":"Access privileges; see Section 5.9 for details"},{"from":"The OID of the data type that corresponds to this table's row type, if any; zero for indexes, sequences, and toast tables, which have no pg_type entry","name":"reltype","to":"The OID of the data type that corresponds to this table's row type, if any; zero for indexes, sequences, and TOAST tables, which have no pg_type entry"}],"from":"18","listing":[],"order":false,"removed":[],"status":"reworded","to":"19","types":[],"unlisted":[]},{"added":[],"attributes":[],"description_changed":false,"descriptions":[{"from":"Number of pages that are marked all-frozen in the table's visibility map. This is only an estimate used for triggering autovacuums. It can also be used along with relallvisible for scheduling manual vacuums and tuning vacuum's freezing behavior. It is updated by VACUUM, ANALYZE, and a few DDL commands such as CREATE INDEX.","name":"relallfrozen","to":"Number of pages that are marked all-frozen in the table's visibility map. This is only an estimate used for triggering autovacuums. It can also be used along with relallvisible for scheduling manual vacuums and tuning vacuum's freezing behavior. It is updated by VACUUM, ANALYZE, and a few DDL commands such as CREATE INDEX.\n\nThis is effectively an unsigned 32-bit integer; values larger than 231−1 are stored as negative values."},{"from":"Number of pages that are marked all-visible in the table's visibility map. This is only an estimate used by the planner. 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It is updated by VACUUM, ANALYZE, and a few DDL commands such as CREATE INDEX.\n\nThis is effectively an unsigned 32-bit integer; values larger than 231−1 are stored as negative values."}],"from":"19","listing":[],"order":false,"removed":[],"status":"reworded","to":"20","types":[],"unlisted":[]}],"column_count":34,"content_hash":"3a6dc8fadabd7b3493e0d85ac1aa2b6546a8b801d98cdb09c9b7646c1f961085","first_version":"7.4","imported_at":"2026-09-30T00:40:55.410695+08:00","kind":"catalog","last_version":"20","name":"pg_class","position":14,"present_in":["7.4","8.0","8.1","8.2","8.3","8.4","9.0","9.1","9.2","9.3","9.4","9.5","9.6","10","11","12","13","14","15","16","17","18","19","20"],"relation_oid":null,"relkind":"r","shared":false,"source_rev":"english-manuals:ea8872f33d2fe5c3e602b22cd56700b9d92f1a106fd1b4da3ff8e1290dd6b8cc","summary":"The catalog pg_class describes tables and other objects that have columns or are otherwise similar to a table.","summary_zh":""}},"Definition":{"Collection":"catalog","Key":"pg_class","SourceDatabase":"center","Version":"18","SourceTable":"catalog","SourceKey":"pg_class","SourceRevision":"english-manuals:ea8872f33d2fe5c3e602b22cd56700b9d92f1a106fd1b4da3ff8e1290dd6b8cc","Facts":{"columns":[{"array_dimensions":0,"attnum":1,"description":"Row identifier","description_zh":"","documented":true,"documented_name":"oid","hidden":false,"name":"oid","not_null":true,"references":"","type":"oid","type_modifier":-1,"type_oid":26},{"array_dimensions":0,"attnum":2,"description":"Name of the table, index, view, etc.","description_zh":"","documented":true,"documented_name":"relname","hidden":false,"name":"relname","not_null":true,"references":"","type":"name","type_modifier":-1,"type_oid":19},{"array_dimensions":0,"attnum":3,"description":"The OID of the namespace that contains this relation","description_zh":"","documented":true,"documented_name":"relnamespace","hidden":false,"name":"relnamespace","not_null":true,"references":"pg_namespace.oid","type":"oid","type_modifier":-1,"type_oid":26},{"array_dimensions":0,"attnum":4,"description":"The OID of the data type that corresponds to this table's row type, if any; zero for indexes, sequences, and toast tables, which have no pg_type entry","description_zh":"","documented":true,"documented_name":"reltype","hidden":false,"name":"reltype","not_null":true,"references":"pg_type.oid","type":"oid","type_modifier":-1,"type_oid":26},{"array_dimensions":0,"attnum":5,"description":"For typed tables, the OID of the underlying composite type; zero for all other relations","description_zh":"","documented":true,"documented_name":"reloftype","hidden":false,"name":"reloftype","not_null":true,"references":"pg_type.oid","type":"oid","type_modifier":-1,"type_oid":26},{"array_dimensions":0,"attnum":6,"description":"Owner of the relation","description_zh":"","documented":true,"documented_name":"relowner","hidden":false,"name":"relowner","not_null":true,"references":"pg_authid.oid","type":"oid","type_modifier":-1,"type_oid":26},{"array_dimensions":0,"attnum":7,"description":"The access method used to access this table or index. Not meaningful if the relation is a sequence or has no on-disk file, except for partitioned tables, where, if set, it takes precedence over default_table_access_method when determining the access method to use for partitions created when one is not specified in the creation command.","description_zh":"","documented":true,"documented_name":"relam","hidden":false,"name":"relam","not_null":true,"references":"pg_am.oid","type":"oid","type_modifier":-1,"type_oid":26},{"array_dimensions":0,"attnum":8,"description":"Name of the on-disk file of this relation; zero means this is a “mapped” relation whose disk file name is determined by low-level state","description_zh":"","documented":true,"documented_name":"relfilenode","hidden":false,"name":"relfilenode","not_null":true,"references":"","type":"oid","type_modifier":-1,"type_oid":26},{"array_dimensions":0,"attnum":9,"description":"The tablespace in which this relation is stored. If zero, the database's default tablespace is implied. 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