Set up docs MCPThese settings are available in system.settings and are autogenerated from source.
use_query_cache
If turned on, SELECT queries may utilize the query cache. Parameters enable_reads_from_query_cache
and enable_writes_to_query_cache control in more detail how the cache is used.
Possible values:
- 0 - Disabled
- 1 - Enabled
use_query_condition_cache
Version history
| Version | Default value | Comment |
|---|---|---|
| 25.4 | 1 | A new optimization |
| 25.3 | 0 | New setting. |
Enable the query condition cache. The cache stores ranges of granules in data parts which do not satisfy the condition in the WHERE clause,
and reuse this information as an ephemeral index for subsequent queries.
Possible values:
- 0 - Disabled
- 1 - Enabled
use_query_condition_cache_for_top_k
Version history
| Version | Default value | Comment |
|---|---|---|
| 26.8 | 1 | New setting to gate the query condition cache for `ORDER BY ... LIMIT n` (TopK) reads; enabled by default. The gate is disabled in 26.7, so `compatibility` with an earlier version keeps it off. |
Enable the query condition cache for queries that use the ORDER BY <column> LIMIT n (TopK) optimization (dynamic filtering or skip-index based). When disabled, such reads neither consult nor populate the cache.
Such queries can drop granules during execution depending on the running threshold, so their cache entries are partitioned by the TopK plan parameters and by the set of parts read. This setting has no effect unless use_query_condition_cache is also enabled.
Possible values:
- 0 - Disabled
- 1 - Enabled