Moving from Oracle to MariaDB
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Help with moving from MySQL to MariaDB, features and compatibility
Answer
Your observations are correct.
MariaDB is not able to push down conditions into non-mergeable derived table subqueries (and neither is MySQL).
Moreover, pushdown would put "id1=1" into HAVING. One also need to be able to push queries down from HAVING into WHERE for this to be efficient. Again, neither MySQL nor MariaDB support this at the moment.
MariaDB has development tasks for this: MDEV-9197, MDEV-7486 and these are considered for the next MariaDB version (10.2).
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