enable_adaptive_codec_selection
When enabled, merges and mutations choose a codec per block for columns that use the default codec (noCODEC clause, or CODEC(Default)).
The candidates are the table’s default codec (see the default_compression_codec setting), NONE, and specialized codecs suited to the column type.
Only integer-like types are currently adaptive.
The smallest output wins. Compression is therefore never worse than the default, and incompressible blocks are stored raw.
A column whose default codec includes encryption (e.g. AES_128_GCM_SIV) is never selected adaptively, so encryption is always applied.
Per-block codecs are reported by the mergeTreeCodecBlockCounts table function.
enable_index_granularity_compression
Compress in memory values of index granularity if it is possibleenable_max_bytes_limit_for_min_age_to_force_merge
If settingsmin_age_to_force_merge_seconds and
min_age_to_force_merge_on_partition_only should respect setting
max_bytes_to_merge_at_max_space_in_pool.
Possible values:
truefalse
enable_mixed_granularity_parts
Enables or disables transitioning to control the granule size with theindex_granularity_bytes setting. Before version 19.11, there was only the
index_granularity setting for restricting granule size. The
index_granularity_bytes setting improves ClickHouse performance when
selecting data from tables with big rows (tens and hundreds of megabytes).
If you have tables with big rows, you can enable this setting for the tables
to improve the efficiency of SELECT queries.
enable_replacing_merge_with_cleanup_for_min_age_to_force_merge
Whether to use CLEANUP merges for ReplacingMergeTree when merging partitions down to a single part. Requiresallow_experimental_replacing_merge_with_cleanup,
min_age_to_force_merge_seconds and min_age_to_force_merge_on_partition_only
to be enabled.
Possible values:
truefalse