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pg_column_size(any)
pg_database_size(oid)
pg_database_size(name)
pg_relation_size(oid)
get_db_source_datasize()
pg_relation_size(text)
pg_relation_size(relation regclass, fork text)
pg_relation_size(relation regclass)
pg_partition_size(oid,oid)
pg_partition_size(text, text)
pg_partition_indexes_size(oid,oid)
pg_partition_indexes_size(text,text)
pg_indexes_size(regclass)
pg_size_pretty(bigint)
pg_size_pretty(numeric)
pg_table_size(regclass)
pg_total_relation_size(oid)
pg_total_relation_size(regclass)
pg_total_relation_size(text)

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Help Center/ GaussDB(DWS)/ SQL Syntax Reference (8.1.3.x)/ Functions and Operators/ Database Object Functions/ Database Object Size Functions

Database Object Size Functions

Updated on 2024-12-19 GMT+08:00

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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.

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