Set up docs MCPThese settings are available in system.merge_tree_settings and are autogenerated from the ClickHouse snapshot.
min_absolute_delay_to_close
Minimal absolute delay to close, stop serving requests and not return Ok during status check.
min_columns_to_activate_adaptive_write_buffer
Allow to reduce memory usage for tables with lots of columns by using adaptive writer buffers.
Compared against the number of streams a wide part writes, which can greatly exceed its number
of columns: a Map with many buckets, or a deeply nested Array or Tuple, writes many streams
for a single column, and one write buffer is allocated per stream.
Possible values:
- 0 - disabled
- 1 - always enabled
min_compress_block_size
Minimum size of blocks of uncompressed data required for compression when writing the next mark. You can also specify this setting in the global settings (see min_compress_block_size setting). The value specified when the table is created overrides the global value for this setting.
min_index_granularity_bytes
Min allowed size of data granules in bytes.
To provide a safeguard against accidentally creating tables with very low
index_granularity_bytes.
min_marks_to_honor_max_concurrent_queries
The minimal number of marks read by the query for applying the max_concurrent_queries setting.
Possible values:
- Positive integer.
0— Disabled (max_concurrent_querieslimit applied to no queries).
Example
<min_marks_to_honor_max_concurrent_queries>10</min_marks_to_honor_max_concurrent_queries>min_merge_bytes_to_use_direct_io
The minimum data volume for merge operation that is required for using direct
I/O access to the storage disk. When merging data parts, ClickHouse calculates
the total storage volume of all the data to be merged. If the volume exceeds
min_merge_bytes_to_use_direct_io bytes, ClickHouse reads and writes the
data to the storage disk using the direct I/O interface (O_DIRECT option).
If min_merge_bytes_to_use_direct_io = 0, then direct I/O is disabled.
min_parts_to_merge_at_once
Minimal amount of data parts which merge selector can pick to merge at once (expert level setting, don’t change if you don’t understand what it is doing). 0 - disabled. Works for Simple and StochasticSimple merge selectors.
min_replicated_logs_to_keep
Keep about this number of last records in ZooKeeper log, even if they are obsolete. It doesn’t affect work of tables: used only to diagnose ZooKeeper log before cleaning.
Possible values:
- Any positive integer.