mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-12-14 18:32:29 +00:00
325c6bdf3d
Reasons: - The cache will at some point store intermediate results as opposed to only query results. We should change the terminology now without having to worry about backward compat. - Equivalent caches in MySQL (1) and Starrocks (2) are called "query cache". - The new name is ca. 13.8% more catchy. (1) https://dev.mysql.com/doc/refman/5.6/en/query-cache.html (2) https://docs.starrocks.io/en-us/2.5/using_starrocks/query_cache
33 lines
909 B
SQL
33 lines
909 B
SQL
-- Tags: no-parallel
|
|
-- Tag no-parallel: Messes with internal cache
|
|
|
|
SET allow_experimental_query_cache = true;
|
|
|
|
-- Start with empty query cache QC and query log
|
|
SYSTEM DROP QUERY CACHE;
|
|
DROP TABLE system.query_log SYNC;
|
|
|
|
-- Run a query with QC on. The first execution is a QC miss.
|
|
SELECT '---';
|
|
SELECT 1 SETTINGS use_query_cache = true;
|
|
|
|
SYSTEM FLUSH LOGS;
|
|
SELECT ProfileEvents['QueryCacheHits'], ProfileEvents['QueryCacheMisses']
|
|
FROM system.query_log
|
|
WHERE type = 'QueryFinish'
|
|
AND query = 'SELECT 1 SETTINGS use_query_cache = true;';
|
|
|
|
|
|
-- Run previous query again with query cache on
|
|
SELECT '---';
|
|
SELECT 1 SETTINGS use_query_cache = true;
|
|
|
|
DROP TABLE system.query_log SYNC;
|
|
SYSTEM FLUSH LOGS;
|
|
SELECT ProfileEvents['QueryCacheHits'], ProfileEvents['QueryCacheMisses']
|
|
FROM system.query_log
|
|
WHERE type = 'QueryFinish'
|
|
AND query = 'SELECT 1 SETTINGS use_query_cache = true;';
|
|
|
|
SYSTEM DROP QUERY CACHE;
|