Compression - hypertable_compression_stats - 《TimescaleDB v2.4 Documentation》

hypertable_compression_stats()

hypertable_compression_stats()

Community

Get statistics related to hypertable compression. All sizes are in bytes.

Required Arguments

Name	Type	Description
`hypertable`	REGCLASS	Hypertable to show stats for.

Returns

Column	Type	Description
`total_chunks`	BIGINT	the number of chunks used by the hypertable
`number_compressed_chunks`	INTEGER	the number of chunks used by the hypertable that are currently compressed
`before_compression_table_bytes`	BIGINT	Size of the heap before compression (NULL if currently uncompressed)
`before_compression_index_bytes`	BIGINT	Size of all the indexes before compression (NULL if currently uncompressed)
`before_compression_toast_bytes`	BIGINT	Size the TOAST table before compression (NULL if currently uncompressed)
`before_compression_total_bytes`	BIGINT	Size of the entire table (table+indexes+toast) before compression (NULL if currently uncompressed)
`after_compression_table_bytes`	BIGINT	Size of the heap after compression (NULL if currently uncompressed)
`after_compression_index_bytes`	BIGINT	Size of all the indexes after compression (NULL if currently uncompressed)
`after_compression_toast_bytes`	BIGINT	Size the TOAST table after compression (NULL if currently uncompressed)
`after_compression_total_bytes`	BIGINT	Size of the entire table (table+indexes+toast) after compression (NULL if currently uncompressed)
`node_name`	TEXT	nodes on which the hypertable is located, applicable only to distributed hypertables

Sample Usage

SELECT * FROM hypertable_compression_stats('conditions');
-[ RECORD 1 ]------------------+------
total_chunks                   | 4
number_compressed_chunks       | 1
before_compression_table_bytes | 8192
before_compression_index_bytes | 32768
before_compression_toast_bytes | 0
before_compression_total_bytes | 40960
after_compression_table_bytes  | 8192
after_compression_index_bytes  | 32768
after_compression_toast_bytes  | 8192
after_compression_total_bytes  | 49152
node_name                      |

Use pg_size_pretty get the output in a more human friendly format.

SELECT pg_size_pretty(after_compression_total_bytes) as total
  FROM hypertable_compression_stats('conditions');
-[ RECORD 1 ]--+------
total | 48 kB