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Add test for statistics on compressed chunks

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Add a test for updating statistics on chunks compressed before
statistics where kept. This patch also sets metadata for previously
compressed chunks so running ANALYZE on them will set the correct
tuplecount.
This commit is contained in:
Sven Klemm 2020-10-15 22:48:02 +02:00 committed by Sven Klemm
parent 7f3feb8200
commit 7fe74d4f07
2 changed files with 117 additions and 51 deletions
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35
sql/updates/latest-dev.sql
View File

@ -29,7 +29,6 @@ AS SELECT * from _timescaledb_catalog.hypertable;
ALTER TABLE _timescaledb_catalog.continuous_aggs_invalidation_threshold DROP CONSTRAINT continuous_aggs_invalidation_threshold_hypertable_id_fkey ;
ALTER TABLE _timescaledb_catalog.hypertable_compression DROP CONSTRAINT hypertable_compression_hypertable_id_fkey ;
CREATE TABLE tmp_hypertable_seq_value AS
SELECT last_value, is_called FROM _timescaledb_catalog.hypertable_id_seq;
ALTER EXTENSION timescaledb DROP TABLE _timescaledb_catalog.hypertable;
@ -124,3 +123,37 @@ DROP TABLE tmp_hypertable_seq_value;
GRANT SELECT ON _timescaledb_catalog.hypertable_id_seq TO PUBLIC;
GRANT SELECT ON _timescaledb_catalog.hypertable TO PUBLIC;
--End Modify hypertable table
-- update metadata for chunks compressed before 2.0
DO $$
DECLARE
plain_chunk RECORD;
comp_chunk TEXT;
rowcount_pre BIGINT;
rowcount_post BIGINT;
BEGIN
FOR plain_chunk IN
SELECT
*
FROM
_timescaledb_catalog.chunk comp
WHERE
compressed_chunk_id IS NOT NULL LOOP
SELECT
format('%I.%I', schema_name, table_name) INTO comp_chunk
FROM
_timescaledb_catalog.chunk
WHERE
id = plain_chunk.compressed_chunk_id;
EXECUTE format('SELECT sum(_ts_meta_count), count(*) FROM %s', comp_chunk) INTO rowcount_pre, rowcount_post;
UPDATE
_timescaledb_catalog.compression_chunk_size
SET
numrows_pre_compression = rowcount_pre,
numrows_post_compression = rowcount_post
WHERE
chunk_id = plain_chunk.id;
END LOOP;
END
$$;

39
test/sql/updates/post.compression.sql
View File

@ -8,9 +8,42 @@ INSERT INTO compress
SELECT g, 'QW', g::text, 2, 0, (100,4)::custom_type_for_compression, false
FROM generate_series('2019-11-01 00:00'::timestamp, '2019-12-15 00:00'::timestamp, '1 day') g;
SELECT count(compress_chunk(chunk.schema_name|| '.' || chunk.table_name)) as count_compressed
FROM _timescaledb_catalog.chunk chunk
SELECT
count(compress_chunk(chunk.schema_name || '.' || chunk.table_name)) AS count_compressed
FROM
_timescaledb_catalog.chunk chunk
INNER JOIN _timescaledb_catalog.hypertable hypertable ON (chunk.hypertable_id = hypertable.id)
WHERE hypertable.table_name = 'compress' and chunk.compressed_chunk_id IS NULL;
WHERE
hypertable.table_name = 'compress'
AND chunk.compressed_chunk_id IS NULL;
SELECT * FROM compress ORDER BY time DESC, small_cardinality;
-- check count and approximate_row_count are the same after analyze
ANALYZE compress;
SELECT
count,
approximate,
CASE WHEN count != approximate THEN
'counts not matching' || random()::TEXT
ELSE
'match'
END AS MATCH
FROM (
SELECT
count(*)
FROM
compress) AS count,
approximate_row_count('compress') AS approximate;
SELECT
hypertable_schema,
hypertable_name,
approximate_row_count(format('%I.%I', hypertable_schema, hypertable_name)::REGCLASS)
FROM
timescaledb_information.hypertables
WHERE
compression_enabled = true
ORDER BY
1,
2;