Not complete yet - still being updated

FeatureMariaDB 5.3/5.5MariaDB 10.0MySQL 5.5MySQL 5.6
Disk access optimizations
Index Condition Pushdown (ICP)YESYES-YES
Disk-sweep Multi-range read (DS-MRR)YESYES-YES
DS-MRR with Key-ordered retrievalYESYES--
Index_merge / Sort_intersectionYESYES--
Cost-based choice of range vs. index_mergeYESYES--
ORDER BY ... LIMIT <small_limit>-YES-YES
Use extended (hidden) primary keys for innodb/xtradbYES (5.5)YES--
Join optimizations
Batched key access (BKA)YESYES-YES
Block hash joinYESYES--
User-set memory limits on all join buffersYESYES--
Apply early outer table ON conditionsYESYES--
Null-rejecting conditions tested early for NULLsYESYES--
Subquery optimizations
In-to-existsYESYESYESYES
Semi-joinYESYES-YES
MaterializationYESYES-YES
NULL-aware MaterializationYESYES--
Cost choice of materialization vs. in-to-existsYESYES-YES
Subquery cacheYESYES--
Fast explain with subqueriesYESYES--
EXISTS-to-IN-YES--
Optimization for derived tables / views
Delayed materialization of derived tables / materialized viewsYESYES-YES
Instant EXPLAIN for derived tablesYESYES-YES
Derived Table with Keys optimizationYESYES-YES
Fields of merge-able views and derived tables used in equality optimizationsYESYES--
Execution control
LIMIT ROWS EXAMINED rows_limitYES (5.5)YES--
Optimizer control (optimizer switch)
Systematic control of all optimizer strategiesYESYES-partial
EXPLAIN improvements
Explain for DELETE, INSERT, REPLACE, and UPDATE-Partial-YES
EXPLAIN in JSON format---YES
More detailed and consistent EXPLAIN for subqueriesYESYES--

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