Enable use of Rowid Filter optimization with eq_ref access.
Use the following assumptions:
- Assume index-only access cost is 50% of non-index-only access cost.
- Take into account that "Eq_ref access cache" reduces the number of
lookups eq_ref access will make.
= This means the number of Rowid Filter checks is reduced also
= Eq_ref access cost is computed using that assumption (see
prev_record_reads() call), so we should use it in all cost '
computations.
This bug manifested itself in very rare situations when splitting
optimization was applied to a materialized derived table with group clause
by key over a constant meargeable derived table that was in inner part of
an outer join. In this case the used tables for the key to access the
split table incorrectly was evaluated to a not empty table map.
Approved by Oleksandr Byelkin <sanja@mariadb.com>
This patch fixes the patch for bug MDEV-30248 that unsatisfactorily
resolved the problem of resolution of references to CTE. In some cases
when such a reference has the same table name as the name of one of
CTEs containing this reference the reference could be resolved incorrectly
that led to an invalid select tree where units could be mutually dependent.
This in its turn could lead to an infinite sequence of recursive calls or
to falls into infinite loops.
The patch also removes LEX::resolve_references_to_cte_in_hanging_cte() as
with the new code for resolution of CTE references the call of this
function is not needed anymore.
Approved by Oleksandr Byelkin <sanja@mariadb.com>
(Initial patch by Varun Gupta. Amended and added comments).
When the query has both
1. Aggregate functions that require sorting data by group, and
2. Window functions
we need to use two temporary tables. The first temp.table will hold the
join output. Then it is passed to filesort(). Reading it in sorted
order allows to compute the aggregate functions.
Then, we need to write their values into the second temp. table. Then,
Window Function computation step can pass that to filesort() and read
them in the order it needs.
Failure to create the second temp. table would cause an assertion
failure: window function could would not find where to get the values
of the aggregate functions.
disable bulk insert optimization if long uniques are used, because they
need to read the table (index_read) after every inserted now. And bulk
insert optimization might disable indexes.
bulk insert is already disabled in other cases when there are chances
that the table will be read duing the bulk insert.
Use SELECT_LEX to save lists for ORDER BY and GROUP BY before parsing
WINDOW clauses / specifications. This is needed for proper parsing
of a nested WINDOW clause when a WINDOW clause is used in a subquery
contained in another WINDOW clause.
Fix assignment of empty SQL_I_List to another one (in case of empty list
next shoud point on first).
Item_singlerow_subselect may be converted to Item_cond during
optimization. So there is a possibility of constructing nested
Item_cond_and or Item_cond_or which is not allowed (such
conditions must be flattened).
This commit checks if such kind of optimization has been applied
and flattens the condition if needed
(Variant 3, initial variant was by Rex Jonston)
A LEFT JOIN with a constant as a column of the inner table produced wrong
query result if the optimizer had to write the inner table column into a
temp table. Query pattern:
SELECT ...
FROM (SELECT /*non-mergeable select*/
FROM t1 LEFT JOIN (SELECT 'Y' as Val) t2 ON ...) as tbl
Fixed this by adding Item_direct_view_ref::save_in_field() which follows
the pattern of Item_direct_view_ref's save_org_in_field(),
save_in_result_field() and val_XXX() functions:
* call check_null_ref() and handle NULL value
* if we didn't get a NULL-complemented row, call Item_direct_ref's function.
it's incorrect to use change_item_tree() to replace arguments
of top-level AND/OR, because they (arguments) are stored in a List,
so a pointer to an argument is in the list_node, and individual
list_node's of top-level AND/OR can be deleted in Item_cond::build_equal_items().
In that case rollback_item_tree_changes() will modify the deleted object.
Luckily, it's not needed to use change_item_tree() for top-level
AND/OR, because the whole top-level item is copied and preserved
in prep_where and prep_on, and restored from there.
So, just don't.
Additionally to the test case in the commit it fixes
* ASAN failure of main.opt_tvc --ps
* ASAN failure of main.having_cond_pushdown --ps
when an internal temporary table field is created from a real field,
a new temp field should only copy a default from the source field
when the latter has it
when creating a temp table field from an actual table field,
these two fields are supposed to be mostly identical
(except for BIT field storage), in particular, temp field should
have the same default as the orig field, even if the sql_mode has
been changed meanwhile (e.g. to include NO_ZERO_DATE)
regression from MDEV-29540 / 8c38939369.
INSERT SELECT errors needed to be unconditionally ignored.
As this touches the CREATE .. SELECT functionality, show
the equalivent test there.
This bug affected queries with nested left joins having the same last inner
table such that not_exists optimization could be applied to the most inner
outer join when optimizer chose to use join buffers. The bug could lead to
producing wrong a result set.
If the WHERE condition a query contains a conjunctive IS NULL predicate
over a non-nullable column of an inner table of a not nested outer join
then not_exists optimization can be applied to tho the outer join. With
this optimization when looking for matches for a certain record from the
outer table of the join the records of the inner table can be ignored
right after the first match satisfying the ON condition is found.
In the case of nested outer joins having the same last inner table this
optimization still can be applied but only if all ON conditions of the
embedding outer joins are satisfied. Such check was missing in the code
that tried to apply not_exists optimization when join buffers were used
for outer join operations.
This problem has been already fixed in the patch for bug MDEV-7992. Yet
there it was resolved only for the cases when join buffers were not used
for outer joins.
Approved by Oleksandr Byelkin <sanja@mariadb.com>
the parser couldn't parse `1=2 not between 3 and 5`
after `2` it expected only NOT2_SYM, but not NOT_SYM
(visible from the sql_yacc.output file), which resulted in
Syntax error ... near 'not between 3 and 4'
The parser was confused by a rather low NOT_SYM precedence and
%prec BETWEEN_SYM didn't resolve this confusion.
As a fix, let's remove any %precedence from NOT_SYM and
specify %prec explicitly in the only place where it matters for NOT_SYM.
In other places, such as for NOT BETWEEN, NOT_SYM won't have a
precedence, so bison won't be confused about it.
The idea is to put Item_direct_ref_to_item as a transparent and
permanent wrapper before a string which require conversion.
So that Item_direct_ref_to_item would be the only place where
the pointer to the string item is stored, this pointer can be changed
and restored during PS execution as needed. And if any permanent
(subquery) optimization would need a pointer to the item,
it'll use a pointer to the Item_direct_ref_to_item - which is
a permanent item and won't go away.
Some tests drop the default mtr database "test". This may fail due
to the directory not being empty. InnoDB may not delete all tables
immediately, due to the "background drop table queue" or its
replacement in commit 1bd681c8b3
(the purge of history would clean up after a DDL operation during
which the server was killed).
Let us try to avoid "drop database test" whenever it is easily possible.
Where it is not, SET GLOBAL innodb_max_purge_lag_wait=0 will ensure
that the replacement of the "background drop table queue" will have
completed its job.
Consistent with MDEV-4206 and empty log_slow_filter still means
no explict filtering. Since 21518ab2e4 however the
log_queries_not_using_indexes became stored in the same variable.
As we need to test for the absense of log_queries_not_using_indexes
the SERVER_QUERY_NO_INDEX USED part of log_slow_statement, the empty
criteria resulted in an always true to log queries not using indexes if
log_slow_filter was set to empty.
Adjusted the log_slow.test for MDEV-4206 as slow_log_query has been
global and session for a while and it was relying on the MDEV-21187
buggy behavior to detect a slow query.
Reviewer: Monty
(Patch from Monty, slightly amended)
Fix rowid filtering optimization in best_access_path():
== Ref access + rowid filtering ==
The cost computations compare #records and index-only scan cost
(keyread_tmp) to find out the per-record advantage one will get if
they skip reading full table record.
The computations produce wrong result when:
- the #records are "clipped down" with s->worst_seeks or
thd->variables.max_seeks_for_key. keyread_tmp is not clipped
this way so the numbers are not comparable.
- access_factor is negative. This means index_only read is
cheaper than non-index-only read.
This patch makes the optimizer not to consider Rowid Filtering in
such cases.
The decision is logged in the Optimizer Trace using
"rowid_filter_skipped" name.
== Range access + rowid filtering ==
when considering to use Rowid Filter with range access, do multiply
keyread_tmp by record_count. That way, it is comparable with the
range access's estimate, which is multiplied by record_count.
The geometry type requires Type:"Feature" but the feature need
not be first in the JSON structure.
Adjust code to return an error if geometry isn't a JSON object,
but continue parsing searching for Type: "Feature" to trigger
the geometry parsing.
Thanks Derick Magnusen for the bug report.
sometimes `KILL QUERY ID @id` was executed before the previous
`send SELECT SLEEP(1000)` has reached the parser. As the statement
resets the kill status before execution, the effect of the KILL
was ignored.
Item_func_not_all::print() either uses Item_func::print() or
directly invokes args[0]->print(). Thus the precedence should be
either the one of Item_func or of args[0].
Item_allany_subselect::print() prints args[0], then a comparison op,
then a subquery. That is, the precedence should be the one of
a comparison.
select_union_direct::send_data() only sends a record when
the LIMIT ... OFFSET clause of the individual select won't skip it.
Thus, select_union_direct::send_data() should not do any actions
related to a sending a record if the offset of a select isn't
reached yet
Like in MDEV-16110 we must release items allocated on thd->mem_root by
reopening the table.
MDEV-16290 relocated MDEV-16110 fix in 10.5 so it works for MDEV-28576
as well. 10.3 without MDEV-16290 now duplicates this fix.
The change from MDEV-29465 exposed a flaw in replace_column_table
where again we were not properly updating the column-level bits.
replace_table_table was changed in MDEV-29465 to properly update
grant_table->init_cols, however replace_column_table still only
modified grant_column->rights when the GRANT_COLUMN already existed.
This lead to a missmatch between GRANT_COLUMN::init_rights and
GRANT_COLUMN::rights, *if* the GRANT_COLUMN already existed.
As an example:
GRANT SELECT (col1) ...
Here:
For col1
GRANT_COLUMN::init_rights and GRANT_COLUMN::rights are set to 1 (SELECT) in
replace_column_table.
GRANT INSERT (col1) ...
Here, without this patch GRANT_COLUMN::init_rights is still 1 and
GRANT_COLUMN::rights is 3 (SELECT_PRIV | INSERT_PRIV)
Finally, if before this patch, one does:
REVOKE SELECT (col1) ...
replace_table_table will see that init_rights loses bit 1 thus it
considers there are no more rights granted on that particular table.
This prompts the whole GRANT_TABLE to be removed via the first revoke,
when the GRANT_COLUMN corresponding to it should still have init_rights == 2.
By also updating replace_column_table to keep init_rights in sync
properly, the issue is resolved.
Reviewed by <serg@mariadb.com>
Commit 32158be added a new test `bad_startup_options`. This test fails
if run as root, which is common on many CI systems.
This test should include `not_as_root.inc` so it is skipped, just
like all other similar tests in MariaDB.
All new code of the whole pull request, including one or several files
that are either new files or modified ones, are contributed under the
BSD-new license. I am contributing on behalf of my employer
Amazon Web Services, Inc.
MDEV-16735 describes how mysql_upgrade fails when alter_algorithm
is set to a value different than 'DEFAULT'/'COPY'. It was marked as
fixed by 0ee0868, but the fix didn't covered the possibility of having
the global value of alter_algorithm set to something different than
'DEFAULT'/'COPY'. To ensure that the upgrade process works properly
regardless the global value of alter_altorithm, this commit force it's
value to 'DEFAULT' (note the quotes) for the mysql_upgrade session.
All new code of the whole pull request, including one or several files
that are either new files or modified ones, are contributed under the
BSD-new license. I am contributing on behalf of my employer
Amazon Web Services, Inc.
