--optimizer-switch

This is a command-line option for the mariadbd & mysqld commands (arg: Required).

In 10.6 CS, 10.5 ES, 10.5 CS:

Fine-tune the optimizer behavior. Takes a comma-separated list of option=value pairs, where value is on, off, or default, and options are: index_merge, index_merge_union, index_merge_sort_union, index_merge_intersection, index_merge_sort_intersection, engine_condition_pushdown, index_condition_pushdown, derived_merge, derived_with_keys, firstmatch, loosescan, materialization, in_to_exists, semijoin, partial_match_rowid_merge, partial_match_table_scan, subquery_cache, mrr, mrr_cost_based, mrr_sort_keys, outer_join_with_cache, semijoin_with_cache, join_cache_incremental, join_cache_hashed, join_cache_bka, optimize_join_buffer_size, table_elimination, extended_keys, exists_to_in, orderby_uses_equalities, condition_pushdown_for_derived, split_materialized, condition_pushdown_for_subquery, rowid_filter, condition_pushdown_from_having, not_null_range_scan

In 10.4 ES, 10.4 CS:

Fine-tune the optimizer behavior. Takes a comma-separated list of option=value pairs, where value is on, off, or default, and options are: index_merge, index_merge_union, index_merge_sort_union, index_merge_intersection, index_merge_sort_intersection, engine_condition_pushdown, index_condition_pushdown, derived_merge, derived_with_keys, firstmatch, loosescan, materialization, in_to_exists, semijoin, partial_match_rowid_merge, partial_match_table_scan, subquery_cache, mrr, mrr_cost_based, mrr_sort_keys, outer_join_with_cache, semijoin_with_cache, join_cache_incremental, join_cache_hashed, join_cache_bka, optimize_join_buffer_size, table_elimination, extended_keys, exists_to_in, orderby_uses_equalities, condition_pushdown_for_derived, split_materialized, condition_pushdown_for_subquery, rowid_filter, condition_pushdown_from_having

In 10.3 ES, 10.3 CS:

Fine-tune the optimizer behavior. Takes a comma-separated list of option=value pairs, where value is on, off, or default, and options are: index_merge, index_merge_union, index_merge_sort_union, index_merge_intersection, index_merge_sort_intersection, engine_condition_pushdown, index_condition_pushdown, derived_merge, derived_with_keys, firstmatch, loosescan, materialization, in_to_exists, semijoin, partial_match_rowid_merge, partial_match_table_scan, subquery_cache, mrr, mrr_cost_based, mrr_sort_keys, outer_join_with_cache, semijoin_with_cache, join_cache_incremental, join_cache_hashed, join_cache_bka, optimize_join_buffer_size, table_elimination, extended_keys, exists_to_in, orderby_uses_equalities, condition_pushdown_for_derived, split_materialized

In 10.2 ES, 10.2 CS:

Fine-tune the optimizer behavior. Takes a comma-separated list of option=value pairs, where value is on, off, or default, and options are: index_merge, index_merge_union, index_merge_sort_union, index_merge_intersection, index_merge_sort_intersection, engine_condition_pushdown, index_condition_pushdown, derived_merge, derived_with_keys, firstmatch, loosescan, materialization, in_to_exists, semijoin, partial_match_rowid_merge, partial_match_table_scan, subquery_cache, mrr, mrr_cost_based, mrr_sort_keys, outer_join_with_cache, semijoin_with_cache, join_cache_incremental, join_cache_hashed, join_cache_bka, optimize_join_buffer_size, table_elimination, extended_keys, exists_to_in, orderby_uses_equalities, condition_pushdown_for_derived

See also: mariadbd & mysqld for MariaDB Community Server 10.6, in 10.5 ES, in 10.5 CS, in 10.4 ES, in 10.4 CS, in 10.3 ES, in 10.3 CS, in 10.2 ES, and in 10.2 CS