Main theme of the patch is to fix joins processing in the plugin
code. We now use SELECT_LEX::top_join_list and process the nested
joins recursively, instead of SELECT_LEX::table_list struct which
we earlier used to build the join filters. The earlier approach
did not process certain nested join ON expressions, causing certain
queries to incorrectly error out such as that described in MCOL-4680.
In addition, some legacy code is also removed.
In this patch, we set the unioned type to a wide decimal, if any of the
numeric columns involved in the union operation have a precision > 18
(which is also possible for BIGINT/UBIGINT types) and <= 38.
We earlier leveraged the server functionality provided by
Item_in_subselect::create_in_to_exists_cond and
Item_in_subselect::inject_in_to_exists_cond
to create and inject the in-to-exists predicate into an IN
subquery's JOIN struct. With this patch, we leave the IN subquery's
JOIN unaltered and instead directly perform this predicate creation
and injection into ColumnStore's select execution plan.
This patch fixes failures in mtr (without --remote) in the following tests:
columnstore/basic.mcs88_import_export_csv
columnstore/basic.mcs47_cpimport_central_loc_sin_source
columnstore/basic.mcs49_cpimport_parallel_dist
columnstore/basic.mcs50_cpimport_stdin
columnstore/basic.mcs55_cpimport_binary_source
columnstore/basic.mcs56_cpimport_negative
columnstore/basic.mcs68_cpimport_datafile_separators
Also fixing the problem with missing UDFs for the affected tests.
(see MCOL-4659 for details):
When mtr runs without --remote, the UDFs must be installed inside
the test using CREATE FUNCTION.
Note, there are still more tests left with missing UDFs. They'll be
fixed separately.
