The XtraDB storage engine was already replaced by InnoDB
and disabled in MariaDB Server 10.2. Let us remove it altogether
to avoid dragging dead code around.
Replace some references to XtraDB with references to InnoDB.
rpl_get_position_info(): Remove.
Remove the mysql-test-run --suite=percona, because it only contains
tests specific to XtraDB, many of which were disabled already in
earlier MariaDB versions.
(Backport to 5.3)
(variant #2, with fixed coding style)
- Make Mrr_ordered_index_reader::resume_read() restore index position
only if it was saved before with Mrr_ordered_index_reader::interrupt_read().
- The crash was caused because the optimizer called handler->multi_range_read_info()
on a derived temporary table. That table has been created, but not opened yet.
Because of that, handler::table was NULL, which caused crash.
Fixed by changing DS-MRR methods to use handler::table_share instead.
handler::table_share is set in handler ctor, so this should be safe.
- "Using MRR" is no longer shown with range access.
- Instead, both range and BKA accesses will show one of the following:
= "Rowid-ordered scan"
= "Key-ordered scan"
= "Key-ordered Rowid-ordered scan"
depending on whether DS-MRR implementation will do scan keys in order, rowids in order,
or both.
- The patch also introduces a way for other storage engines/MRR implementations to
pass information to EXPLAIN output about the properties of employed MRR scans.
- The problem was that Mrr_ordered_index_reader's interrupt_read() and resume_read() would
save and restore 1) index tuple 2) the rowid (as bytes returned by handler->position()). Clustered
primary key columns were not saved/restored.
They are not explicitly present in the index tuple (i.e. table->key_info[secondary_key].key_parts
doesn't list them), but they are actually there, in particular
table->field[clustered_primary_key_member].part_of_key(secondary_key) == 1. Index condition pushdown
code [correctly] uses the latter as inidication that pushed index condition can refer to clustered PK
members.
The fix was to make interrupt_read()/resume_read() to save/restore clustered primary key members as well,
so that we get correct values for them when evaluating pushed index condition.
[3rd attempt: remove the debugging aids, fix comments in testcase]
Switch from "Disable identical key handling optimization when
IndexConditionPushdown is used" approach
To
an approach where we save/restore index tuple and so can use index condition pushdown.
- Make Mrr_ordered_index_reader() save the rowid across scan interruptions
Also
- Fix compiler warning for setup_buffer_sizes()
- Add commented key_copy/key_restore for better handling of a similar issue
with index record being destroyed by scan interruption (which causes
incorrect evaluation of pushed index condition later on).
