> For the complete documentation index, see [llms.txt](https://mariadb.com/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://mariadb.com/docs/release-notes/community-server/about/compatibility-and-differences/optimizer-feature-comparison-matrix.md). # Optimizer Feature Comparison Matrix The below is a table view. For a more graphical view of the differences see [What is the difference between MySQL and MariaDB query optimizers](/docs/release-notes/community-server/about/compatibility-and-differences/differences-between-the-mysql-and-mariadb-query-optimizer.md). | Feature | [MariaDB 5.3](/docs/release-notes/community-server/old-releases/5.3/changes-improvements-in-mariadb-5-3.md)/5.5 | [MariaDB 10.0](/docs/release-notes/community-server/old-releases/10.0/changes-improvements-in-mariadb-10-0.md) | MySQL 5.5 | MySQL 5.6 | | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | --------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------- | --------- | --------- | | Disk access optimizations | | | | | | [Index Condition Pushdown](/docs/server/ha-and-performance/optimization-and-tuning/query-optimizations/index-condition-pushdown.md) (ICP) | YES | YES | - | YES | | [Disk-sweep Multi-range read](/docs/server/ha-and-performance/optimization-and-tuning/mariadb-internal-optimizations/multi-range-read-optimization.md) (DS-MRR) | YES | YES | - | YES | | [DS-MRR with Key-ordered retrieval](/docs/server/ha-and-performance/optimization-and-tuning/mariadb-internal-optimizations/multi-range-read-optimization.md) | YES | YES | - | - | | [Index\_merge / Sort\_intersection](/docs/server/ha-and-performance/optimization-and-tuning/query-optimizations/index_merge-sort_intersection.md) | YES | YES | - | - | | Cost-based choice of range vs. index\_merge | YES | YES | - | - | | ORDER BY ... LIMIT \ | - | YES | - | YES | | Use extended (hidden) primary keys for innodb/xtradb | YES (5.5) | YES | - | - | | Join optimizations | | | | | | [Batched key access](https://github.com/mariadb-corporation/docs-server/blob/test/release-notes/compatibility-and-differences/broken-reference/README.md) (BKA) | YES | YES | - | YES | | [Block hash join](https://github.com/mariadb-corporation/docs-server/blob/test/release-notes/compatibility-and-differences/broken-reference/README.md) | YES | YES | - | - | | User-set memory limits on all join buffers | YES | YES | - | - | | Apply early outer table ON conditions | YES | YES | - | - | | Null-rejecting conditions tested early for NULLs | YES | YES | - | - | | Subquery optimizations | | | | | | [In-to-exists](/docs/server/ha-and-performance/optimization-and-tuning/query-optimizations/subquery-optimizations/non-semi-join-subquery-optimizations.md#the-in-to-exists-transformation) | YES | YES | YES | YES | | [Semi-join](/docs/server/ha-and-performance/optimization-and-tuning/query-optimizations/subquery-optimizations/semi-join-subquery-optimizations.md) | YES | YES | - | YES | | [Materialization](/docs/server/ha-and-performance/optimization-and-tuning/query-optimizations/optimization-strategies/semi-join-materialization-strategy.md) | YES | YES | - | YES | | NULL-aware Materialization | YES | YES | - | - | | Cost choice of materialization vs. in-to-exists | YES | YES | - | YES | | [Subquery cache](/docs/server/ha-and-performance/optimization-and-tuning/query-optimizations/subquery-optimizations/subquery-cache.md) | YES | YES | - | - | | Fast explain with subqueries | YES | YES | - | - | | [EXISTS-to-IN](/docs/server/ha-and-performance/optimization-and-tuning/query-optimizations/subquery-optimizations/exists-to-in-optimization.md) | - | YES | - | - | | Optimization for derived tables / views | | | | | | Delayed materialization of derived tables / materialized views | YES | YES | - | YES | | Instant EXPLAIN for derived tables | YES | YES | - | YES | | Derived Table with Keys optimization | YES | YES | - | YES | | Fields of merge-able views and derived tables used in equality optimizations | YES | YES | - | - | | Execution control | | | | | | LIMIT ROWS EXAMINED rows\_limit | YES (5.5) | YES | - | - | | Optimizer control (optimizer switch) | | | | | | Systematic control of all optimizer strategies | YES | YES | - | partial | | EXPLAIN improvements | | | | | | [Explain for DELETE, INSERT, REPLACE, and UPDATE](/docs/server/reference/sql-statements/administrative-sql-statements/analyze-and-explain-statements/explain.md) | - | Partial | - | YES | | EXPLAIN in JSON format | - | - | - | YES | | [More detailed and consistent EXPLAIN for subqueries](/docs/server/reference/sql-statements/administrative-sql-statements/analyze-and-explain-statements/explain.md) | YES | YES | - | - | | Optimizer trace | | | | | | Optimizer trace | - | - | - | YES | *This page is licensed: CC BY-SA / Gnu FDL* {% @marketo/form formid="4316" formId="4316" %} --- # Agent Instructions This documentation is published with GitBook. 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