Database Object Size Functions

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.

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postgres=#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:

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postgres=#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:

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postgres=#analyze;
ANALYZE
postgres=#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.

pg_obs_file_size(regclass)

Description: This function obtains the CU file size, file name, and bucket ID stored on OBS by specifying the OID or name of a V3 column-store table. This function is supported only by clusters of version 9.1.0 or later.

Parameter: The input parameter can be the table OID or table name.

Return type: record

Example:

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SELECT * FROM pg_obs_file_size('t3_col_part_dif_partition');
 bucketid |     filename     | size
----------+------------------+------
        9 | 23488119324673.0 |  512
       22 | 23488102760449.0 |  512
       21 | 23488119521281.0 |  512
       16 | 23488102662145.0 |  512
(4 rows)

pg_obs_file_size(text, text)

Description: This function specifies a partition of a column-store V3 table (primary table name or partitioned table) and returns the size, file name, and bucket ID of the CU file stored on OBS. This function is supported only by clusters of version 9.1.0 or later.

Parameter: The input parameter can be the table OID or table name. The partition name is used as the partition name.

Return type: record