Database Object Size Functions¶
Database object size functions calculate the actual disk space used by database objects.
pg_column_size(any)¶
Description: Specifies the number of bytes used to store a particular value (possibly compressed).
Return type: integer
Note: pg_column_size displays the space for storing an independent data value.
SELECT pg_column_size(1);
pg_column_size
----------------
4
(1 row)
pg_database_size(oid)¶
Description: Specifies the disk space used by the database with the specified OID.
Return type: bigint
pg_database_size(name)¶
Description: Specifies the disk space used by the database with the specified name.
Return type: bigint
Note: pg_database_size receives the OID or name of a database and returns the disk space used by the corresponding object.
Example:
SELECT pg_database_size('gaussdb');
pg_database_size
------------------
51590112
(1 row)
pg_relation_size(oid)¶
Description: Specifies the disk space used by the table with a specified OID or index.
Return type: bigint
get_db_source_datasize()¶
Description: Estimates the total size of non-compressed data in the current database.
Return type: bigint
Note: (1) ANALYZE must be performed before this function is called. (2) Calculate the total size of non-compressed data by estimating the compression rate of column-store tables.
Example:
analyze;
ANALYZE
SELECT get_db_source_datasize();
get_db_source_datasize
------------------------
35384925667
(1 row)
pg_relation_size(text)¶
Description: Specifies the disk space used by the table with a specified name or index. The table name can be schema-qualified.
Return type: bigint
pg_relation_size(relation regclass, fork text)¶
Description: Specifies the disk space used by the specified bifurcating tree ('main', 'fsm', or 'vm') of a certain table or index.
Return type: bigint
pg_relation_size(relation regclass)¶
Description: Is an abbreviation of pg_relation_size(..., 'main').
Return type: bigint
Note: pg_relation_size receives the OID or name of a table, index, or compressed table, and returns the size.
pg_partition_size(oid,oid)¶
Description: Specifies the disk space used by the partition with a specified OID. The first oid is the OID of the table and the second oid is the OID of the partition.
Return type: bigint
pg_partition_size(text, text)¶
Description: Specifies the disk space used by the partition with a specified name. The first text is the table name and the second text is the partition name.
Return type: bigint
pg_partition_indexes_size(oid,oid)¶
Description: Specifies the disk space used by the index of the partition with a specified OID. The first oid is the OID of the table and the second oid is the OID of the partition.
Return type: bigint
pg_partition_indexes_size(text,text)¶
Description: Specifies the disk space used by the index of the partition with a specified name. The first text is the table name and the second text is the partition name.
Return type: bigint
pg_indexes_size(regclass)¶
Description: Specifies the total disk space used by the index appended to the specified table.
Return type: bigint
pg_size_pretty(bigint)¶
Description: Converts the calculated byte size into a size readable to human beings.
Return type: text
pg_size_pretty(numeric)¶
Description: Converts the calculated byte size indicated by a numeral into a size readable to human beings.
Return type: text
Note: pg_size_pretty formats the results of other functions into a human-readable format. KB/MB/GB/TB can be used.
pg_table_size(regclass)¶
Description: Specifies the disk space used by the specified table, excluding indexes (but including TOAST, free space mapping, and visibility mapping).
Return type: bigint
pg_total_relation_size(oid)¶
Description: Specifies the disk space used by the table with a specified OID, including the index and the compressed data.
Return type: bigint
pg_total_relation_size(regclass)¶
Description: Specifies the total disk space used by the specified table, including all indexes and TOAST data.
Return type: bigint
pg_total_relation_size(text)¶
Description: Specifies the disk space used by the table with a specified name, including the index and the compressed data. The table name can be schema-qualified.
Return type: bigint
Note: pg_total_relation_size receives the OID or name of a table or a compressed table, and returns the sizes of the data, related indexes, and the compressed table in bytes.