hypertable_compression_stats()

Get hypertable statistics related to compression

Since 1.5.0

Old API since v2.18.0. Superseded by hypertable_columnstore_stats(). However, compression APIs are still supported, you do not need to migrate to the hypercore APIs.

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

For more information about using s, including size partitioning, see the hypertable section.

For more information about compression, see the compression section.

Samples

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

Arguments

The syntax is:

SELECT * FROM hypertable_compression_stats(
    hypertable = '<hypertable_name>'
);

Name	Type	Default	Required	Description
hypertable	REGCLASS	-	✔	to show statistics for

Returns

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

Returns show NULL if the data is currently uncompressed.