Analysis:
st_select_lex_unit::prepare() computes can_skip_order_by as TRUE.
As a result join->prepare() gets called with order == NULL, and
doesn't do name resolution for the inner ORDER clause. Due to this
the prepare phase doesn't detect that the query references non-exiting
function and field.
Later join->optimize() calls update_used_tables() for a non-resolved
Item_field, which understandably has no Field object. This call results
in a crash.
Solution:
Resolve unnecessary ORDER BY clauses to detect if they reference non-exising
objects. Then remove such clauses from the JOIN object.
MDEV-5034:Wrong result on LEFT JOIN with a SELECT SQ or a merge view, UNION in IN subquery
Make reset null_row same as it was set in evaluate_null_complemented_join_record().
The problem was that view firlds detect null_row by not-yet-reset table.
The bug caused a memory overwrite in the function update_ref_and_keys()
It happened due to a wrong value of SELECT_LEX::cond_count. This value
historically was calculated by the fix_fields method. Now the logic of
calling this method became too complicated and, as a result, this value
is calculated not always correctly.
The patch changes the way how and when the values of SELECT_LEX::cond_count
and of SELECT_LEX::between_count are calculated. The new code does it just at
the beginning of update_ref_and_keys().
Apparently in a general case a short-cut for the distinct optimization
is invalid if join buffers are used to join tables after the tables whose
values are to selected.
Other fix of maybe_null problem and revert of revno: 3608 "MDEV-3873 & MDEV-3876 & MDEV-3912 : Wrong result (extra rows) with ALL subquery from a MERGE view."
* add TokuDB, together with the ft-index library
* cmake support, auto-detecting whether tokudb can be built
* fix packaging - tokudb-engine.rpm, deb
* remove PBXT
* add jemalloc
* the server is built with jemalloc by default even if TokuDB is not built
* documentation files in RPM are installed in the correct location
* support for optional deb packages (tokudb has specific build requirements)
* move plugins from mariadb-server deb to appropriate debs (server/test/libmariadbclient)
* correct mariadb-test.deb to be not architecture-independent
* fix out-of-tree builds to never modify in-tree files
* new handler::prepare_index_scan() method
ORDER BY does not work
Use "dynamic" row format (instead of "block") for MARIA internal
temporary tables created for cursors.
With "block" row format MARIA may shuffle rows, with "dynamic" row
format records are inserted sequentially (there are no gaps in data
file while we fill temporary tables).
This is needed to preserve row order when scanning materialized cursors.
When a non-nullable datetime field is used under an IS NULL predicate
of the WHERE condition in a query with outer joins the remove_eq_conds
function should check whether this field belongs to an inner table
of any outer join that can be, in a general case, a nested outer join.
When in function remove_eq_conds() a sub-formula of the processed condition
is replaced for another formula we should ensure that in the resulting
formula AND/OR levels must alternate.
The patch to fix mdev-4418 turned out to be incorrect.
At the substitution of single row tables in make_join_statistics()
the used multiple equalities may change and references to the new multiple
equalities must be updated. The function remove_eq_conds() takes care of it and
it should be called right after the substitution of single row tables.
Calling it after the call of make_join_statistics was a mistake.
The code of JOIN::optimize that performed substitutions for the best equal
field in all ref items did not take into account that a multiple equality
could contain the result of the single-value subquery if the subquery is
inexpensive. This code was corrected.
Also made necessary corresponding corrections in the code of make_join_select().
After single row substitutions there might appear new equalities.
They should be properly propagated to all AND/OR levels the WHERE
condition. It's done now with an additional call of remove_eq_conds().
This patch almost totally revised the patch for bug mdev-4177.
The latter had too many defects. In particular, it did not
propagate multiple equalities formed when merging a degenerate
disjunct into underlying AND formula.
This a an old legacy performance bug.
When a very selective range scan existed for the second table in a join,
and, at the same time, there was another range condition depending on the
fields of the first table, the optimizer chose a plan with
'Range checked for each record'. This plan was extremely inefficient in
comparison with the regular selective range scan.
As a matter of fact the range scan chosen for each record was the same as
that selective range scan.
Changed the test case for bug 24776 to preserve the old output for explain.
In the case of loose scan used as input for order by, end_send()
didn't detect correctly that a loose scan was used, and didn't copy
the non-aggregated fields from the temp table used for ORDER BY.
The fix uses the fact that the quick select used for sorting is
attached to JOIN::pre_sort_join_tab instead of JOIN::join_tab.
