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hypertable_compression_stats.md

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api_name hypertable_compression_stats()
excerpt Get hypertable statistics related to compression
topics
compression
keywords
compression
hypertables
information
tags
statistics
size
api
license type
community
function
products
cloud
mst
self_hosted

import Deprecated2180 from "versionContent/_partials/_deprecated_2_18_0.mdx";

hypertable_compression_stats() Community

Superseded by hypertable_columnstore_stats().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 hypertable compression. All sizes are in bytes.

For more information about using hypertables, including chunk 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

Required arguments

Name Type Description
hypertable REGCLASS Hypertable to show statistics for

Returns

Column Type Description
total_chunks BIGINT The number of chunks used by the hypertable
number_compressed_chunks BIGINT The number of chunks used by the hypertable 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 hypertable is located, applicable only to distributed hypertables

Returns show NULL if the data is currently uncompressed.