row_search_idx_cond_check with rowid_filter upon concurrent access to table
This bug has nothing to do with the concurrent access to table. Rather it
concerns queries for which the optimizer decides to employ a rowid filter
when accessing an InnoDB table by a secondary index, but later when
calling test_if_skip_sort_order() changes its mind to access the table by
the primary key.
Currently usage of rowid filters is not supported in InnoDB if the table
is accessed by the primary key. So in this case usage of a rowid filter
to access the table must be prohibited.
In this scenario:
- There is a possible range access for table T
- And there is a ref access on the same index which uses fewer key parts
- The join optimizer picks the ref access (because it is cheaper)
- make_join_select applies this heuristic to switch to range:
/* Range uses longer key; Use this instead of ref on key */
Join buffer will be used without having called
JOIN_TAB::make_scan_filter(). This means, conditions that should be
checked when reading table T will be checked after T is joined with the
contents of the join buffer, instead.
Fixed this by adding a make_scan_filter() check.
(updated patch after backport to 10.3)
(Fix testcase on Windows)
The issue here is for degenerate joins we should execute the window
function but it is not getting executed in all the cases.
To get the window function values window function needs to be executed
always. This currently does not happen in few cases
where the join would return 0 or 1 row like
1) IMPOSSIBLE WHERE
2) MIN/MAX optimization
3) EMPTY CONST TABLE
The fix is to make sure that window functions get executed
and the temporary table is setup for the execution of window functions
The query requires 2 temporary tables for execution, the window function
is always attached to the last temporary table, but in this case the
result field of the window function points to the first temporary table
rather than the last one.
Fixed this by not changing window function items with temporary table
items of the first temporary table.
Don't do skip_setup_conds() unless all errors are checked.
Fixes following errors:
ER_PERIOD_NOT_FOUND
ER_VERS_QUERY_IN_PARTITION
ER_VERS_ENGINE_UNSUPPORTED
ER_VERS_NOT_VERSIONED
Don't do skip_setup_conds() unless all errors are checked.
Fixes following errors:
ER_PERIOD_NOT_FOUND
ER_VERS_QUERY_IN_PARTITION
ER_VERS_ENGINE_UNSUPPORTED
ER_VERS_NOT_VERSIONED
in row_search_idx_cond_check
When usage of rowid filter is evaluated by the optimizer to join a table
to the current partial join employing a certain index it should be checked
that a key for at least the major component of this index can be constructed
using values from the columns of the partial join.
in row_search_idx_cond_check
For a single table query with ORDER BY and several sargable range
conditions the optimizer may choose an execution plan that employs
a rowid filter. In this case it is important to build the filter before
calling the function JOIN_TAB::sort_table() that creates sort index
for the result set, because when this is index created the filter has
to be already filled. After the sort index has been created the
filter must be deactivated. If not to do this the innodb function
row_search_idx_cond_check() is getting confused when it has to read rows
from the created sort index by using ha_rnd_pos().
The order of actions mentioned above is needed also when processing a
join query if sorting is performed for the first non constant table in
the chosen execution plan.
MDEV-18957 UPDATE with LIMIT clause is wrong for versioned partitioned tables
UPDATE, DELETE: replace linear search of current/historical records
with vers_setup_conds().
Additional DML cases in view.test
Count the "gap" time between table accesses and display it as
r_other_time_ms in the "table" element.
* The advantage of this approach is that it doesn't add any new
my_timer_cycles() calls.
* The disadvantage is that the definition of what is done during
"other time" is not that clear: it includes checking the WHERE
(for this table), constructing index lookup tuple (for the next table)
writing to GROUP BY temporary table (as we dont account for that time
separately [yet], etc)
The issue here is the wrong estimate of the cardinality of a partial join,
the cardinality is too high because the function table_cond_selectivity()
returns an absurd number 100 while selectivity cannot be greater than 1.
When accessing table t by outer reference t1.a via index we do not perform any
range analysis for t. Yet we see TABLE::quick_key_parts[key] and
TABLE->quick_rows[key] contain a non-zero value though these should have been
remained untouched and equal to 0.
Thus real cause of the problem is that TABLE::init does not clean the arrays
TABLE::quick_key_parts[] and TABLE::>quick_rows[].
It should have done it because the TABLE structure created for any
instance of a table can be reused for many queries.
A conflict between MDEV-19514 (b42294bc64)
and MDEV-20934 (d7a2401750)
was resolved. We will not invoke the function ibuf_delete_recs()
from ibuf_merge_or_delete_for_page(). Instead, we will add that
logic to the function ibuf_read_merge_pages().
In the function prev_record_reads where one finds the different row combinations for a
subset of partial join, it did not take into account the selectivity of tables
involved in the subset of partial join.
because internally setup_wild() adjusts select_lex->with_wild directly
anyway, so there is no reason to pretend that the number of '*' may be
anything else but select_lex->with_wild
And don't update select_lex->item_list, because fields can come
from anywhere and don't necessarily have to be copied into select_lex.
Now both offset and limit are stored and do not chenged during execution
(offset is decreased during processing in versions before 10.5).
(Big part of this changes made by Monty)
