These settings are available in system.merge_tree_settings and are autogenerated from ClickHouse source.
text_index_dictionary_block_frontcoding_compression
Default front-coding compression for text index dictionary blocks.
Can be overridden by explicit dictionary_block_frontcoding_compression index argument.
text_index_dictionary_block_size
Default dictionary block size for text indexes.
Can be overridden by explicit dictionary_block_size index argument.
text_index_max_memory_usage_before_flush
Maximum estimated memory retained by a text index builder before flushing a temporary segment.
text_index_max_processed_tokens_before_flush
Maximum number of processed tokens accumulated by a text index builder before flushing a temporary segment.
text_index_posting_list_block_size
Default posting list block size for text indexes (rows).
Can be overridden by explicit posting_list_block_size index argument.
text_index_posting_list_codec
Default posting list codec for text indexes. One of none, bitpacking, pfor.
Can be overridden by explicit posting_list_codec index argument.
text_index_serialization_version
The preferred on-disk serialization format version for writing text indexes.
The setting is a preference rather than a hard constraint: if the configured version cannot
represent an index, a newer version that can represent it is chosen automatically, and
writing a text index never fails because of this setting.
During a rolling upgrade, pin the format with the profile-level compatibility setting on
the already upgraded servers, so that they keep writing the format that older servers can still read.
Possible values:
v0_initial — The original format. Does not persist the posting list codec type.v1_with_codec — Persists the posting list codec type in the text index header.v2_with_positions — Persists token positions for indexes with support_phrase_search.
Last modified on September 20, 2026
