Subselect executes twice, at JOIN::optimize stage
and at JOIN::execute stage. At optimize stage
Innodb prebuilt struct which is used for the
retrieval of column values is initialized in.
ha_innobase::index_read(), prebuilt->sql_stat_start is true.
After QUICK_ROR_INTERSECT_SELECT finished his job it
restores read_set/write_set bitmaps with initial values
and deactivates one of the handlers used by
QUICK_ROR_INTERSECT_SELECT in JOIN::cleanup
(it's the case when we reuse original handler as one of
handlers required by QUICK_ROR_INTERSECT_SELECT object).
On second subselect execution inactive handler is activated
in QUICK_RANGE_SELECT::reset, file->ha_index_init().
In ha_index_init Innodb prebuilt struct is reinitialized
with inappropriate read_set/write_set bitmaps. Further
reinitialization in ha_innobase::index_read() does not
happen as prebuilt->sql_stat_start is false.
It leads to partial retrieval of required field values
and we get a mix of field values from different records
in the record buffer.
The fix is to reset
read_set/write_set bitmaps as these values
are required for proper intialization of
internal InnoDB struct which is used for
the retrieval of column values
(see build_template(), ha_innodb.cc)
WL#3397 Refactoring storage engine test cases (for falcon)
It contains also fixes according to code review.
Contents: Testcases which were in history dedicated to InnoDB or MyISAM only.
Modifications:
1. Shift the main testing code into include/<testing field>.inc
Introduce $variables which can be used to omit tests for features which are not supported by
certain storage engines.
2. The storage engine to be tested is assigned within the toplevel script (t/<whatever>_<engine>.test)
via variable $engine_type and the the main testing code is sourced from
include/<testing field>.inc
3. Some toplevel testscripts have to be renamed to
- avoid immediate or future namespace clashes
- show via filename which storage engine is tested
4. Minor code cleanup like remove trailing spaces, some additional comments ....
- Make the range-et-al optimizer produce E(#table records after table
condition is applied),
- Make the join optimizer use this value,
- Add "filtered" column to EXPLAIN EXTENDED to show
fraction of records left after table condition is applied
- Adjust test results, add comments
* Removed unused parameters
* Fixed several cost calculation errors in ror_intersect_add
* Better code structure for ror_intersect_add and get_best_ror_intersect
* Fixed a problem with wrong query results for partially covering keys in ROR-index_merge
* ROR-intersection retrieval plan choice algorithm now uses less disk IO
- and properly processes clustered PK range scans
* Fixed several minor range optimizer problems
* Added more comments
* Code cleanup
