recompress_chunk()

Recompresses a compressed chunk that had more data inserted after compression.

2. recompress_chunk(

4. chunk REGCLASS,

6. if_not_compressed BOOLEAN = false

8. )

You can also recompress chunks by running the job associated with your compression policy. recompress_chunk gives you more fine-grained control by allowing you to target a specific chunk.

important

recompress_chunk is implemented as an SQL procedure and not a function. Call the procedure with CALL. Don’t use a SELECT statement.

note

recompress_chunk only works on chunks that have previously been compressed. To compress a chunk for the first time, use compress_chunk.

Required arguments

Optional arguments

Sample usage

Recompress the chunk timescaledb_internal._hyper_1_2_chunk:

2. CALL recompress_chunk('_timescaledb_internal._hyper_1_2_chunk');

Troubleshooting

In TimescaleDB 2.6.0 and above, recompress_chunk is implemented as a procedure. Previously, it was implemented as a function. If you are upgrading to TimescaleDB 2.6.0 or above, therecompress_chunk function could cause an error. For example, trying to run SELECT recompress_chunk(i.show_chunks, true) FROM... gives the following error:

2. ERROR:  recompress_chunk(regclass, boolean) is a procedure

To fix the error, use CALL instead of SELECT. You might also need to write a procedure to replace the full functionality in your SELECT statement. For example:

2. DO $$

4. DECLARE chunk regclass;

6. BEGIN

8. FOR chunk IN SELECT format('%I.%I', chunk_schema, chunk_name)::regclass

10. FROM timescaledb_information.chunks

12. WHERE is_compressed = true

14. LOOP

16. RAISE NOTICE 'Recompressing %', chunk::text;

18. CALL recompress_chunk(chunk, true);

20. END LOOP;

22. END

24. $$;