If translation table present when we materialize the derived table then
change it to point to the materialized table.
Added debug info to see really what happens with what derived.
This bug manifests due to wrong computation and evaluation of
keyinfo->key_length. The issues were:
* Using table->file->max_key_length() as an absolute value that must not be
reached for a key, while it represents the maximum number of bytes
possible for a table key.
* Incorrectly computing the keyinfo->key_length size during
KEY_PART_INFO creation. The metadata information regarding the key
such the field length (for strings) was added twice.
Do not use merge_for_insert for commands which use SELECT because optimizer can't work with such tables.
Fixes which makes multi-delete working with normally merged views.
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."
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.
WITH COMPOSITE KEY COLUMNS
Problem:-
While running a SELECT query with several AGGR(DISTINCT) function
and these are referring to different field of same composite key,
Returned incorrect value.
Analysis:-
In a table, where we have composite key like (a,b,c)
and when we give a query like
select COUNT(DISTINCT b), SUM(DISTINCT a) from ....
here, we first make a list of items in Aggr(distinct) function
(which is a, b), where order of item doesn't matter.
and then we see, whether we have a composite key where the prefix
of index columns matches the items of the aggregation function.
(in this case we have a,b,c).
if yes, so we can use loose index scan and we need not perform
duplicate removal to distinct in our aggregate function.
In our table, we traverse column marked with <-- and get the result as
(a,b,c) count(distinct b) sum(distinct a)
treated as count b treated as sum(a)
(1,1,2)<-- 1 1
(1,2,2)<-- 1++=2 1+1=2
(1,2,3)
(2,1,2)<-- 2++=3 1+1+2=4
(2,2,2)<-- 3++=4 1+1+2+2=6
(2,2,3)
result will be 4,6, but it should be (2,3)
As in this case, our assumption is incorrect. If we have
query like
select count(distinct a,b), sum(distinct a,b)from ..
then we can use loose index scan
Solution:-
In our query, when we have more then one aggr(distinct) function
then they should refer to same fields like
select count(distinct a,b), sum(distinct a,b) from ..
-->we can use loose scan index as both aggr(distinct) refer to same fields a,b.
If they are referring to different field like
select count(distinct a), sum(distinct b) from ..
-->will not use loose scan index as both aggr(distinct) refer to different fields.
sql/sql_table.cc:
Remove version protection from share when repair has been done.
Without this one can't run SHOW commands on the table if it was locked until it's unlocked.
sql/table.h:
Allow one to remove version protection with allow_access_to_protected_table()
The issue was that there was that SHOW commands could open the table in the store engine, even in cases
where it should not be allowed to do that (ie, the storage engines meta data for that table was under big changes).
The cases where this should not be allowed are:
- ALTER TABLE DISABLE KEYS
- ALTER TABLE ENABLE KEYS
- REPAIR TABLE
- OPTIMIZE TABLE
- DROP TABLE
This patch adds a new mode, protected_against_usage(). If this is used then the SHOW command will wait until the table
is accessable. This is implemented by re-using the already exising 'version' flag for TABLE_SHARE.
It also added functions to be used to change TABLE_SHARE->version instead of changing it directly.
mysql-test/r/myisam-metadata.result:
Added test case
mysql-test/t/myisam-metadata.test:
Added test case
sql/mysqld.cc:
Start from refresh_version 2 as 0 and 1 are reserved.
sql/sql_admin.cc:
Added MYSQL_OPEN_FOR_REPAIR
Updated call to wait_while_table_is_used()
sql/sql_base.cc:
Updated call to wait_while_table_is_used()
- Allow one to specify how the table should be removed (for all commands except show or for all commands).
- Don't allow one to reopen the table if one has called share->protect_against_usage()
sql/sql_base.h:
Added TDC_RT_REMOVE_NOT_OWN_AND_MARK_NOT_USABLE, which is used to mark that no one can reopen this table, except with MYSQL_OPEN_FOR_REPAIR .
- Added MYSQL_OPEN_FOR_REPAIR
- Updated prototype for wait_while_table_is_used()
sql/sql_table.cc:
Updated call to wait_while_table_is_used()
Use MYSQL_OPEN_FOR_REPAIR for open tables that where repaired.
sql/sql_truncate.cc:
Updated call to wait_while_table_is_used()
sql/table.cc:
Use set_refresh_version()
sql/table.h:
Added functions to be used to change TABLE_SHARE->version instead of changing it directly
If triggers are used for an insert/update/delete statement than the values of
all virtual columns must be computed as any of them may be used by the triggers.
LP bug #1035225 / MySQL bug #66301: INSERT ... ON DUPLICATE KEY UPDATE +
innodb_autoinc_lock_mode=1 is broken
The problem was that when certain INSERT ... ON DUPLICATE KEY UPDATE
were executed concurrently on a table containing an AUTO_INCREMENT
column as a primary key, InnoDB would correctly reserve non-overlapping
AUTO_INCREMENT intervals for each statement, but when the server
encountered the first duplicate key error on the secondary key in one of
the statements and performed an UPDATE, it also updated the internal
AUTO_INCREMENT value to the one from the existing row that caused a
duplicate key error, even though the AUTO_INCREMENT value was not
specified explicitly in the UPDATE clause. It would then proceed with
using AUTO_INCREMENT values the range reserved previously by another
statement, causing duplicate key errors on the AUTO_INCREMENT column.
Fixed by changing write_record() to ensure that in case of a duplicate
key error the internal AUTO_INCREMENT counter is only updated when the
AUTO_INCREMENT value was explicitly updated by the UPDATE
clause. Otherwise it is restored to what it was before the duplicate key
error, as that value is unused and can be reused for subsequent
successfully inserted rows.
sql/sql_insert.cc:
Don't update next_insert_id to the value of a row found during ON DUPLICATE KEY UPDATE.
sql/sql_parse.cc:
Added DBUG_SYNC
sql/table.h:
Added next_number_field_updated flag to detect changing of auto increment fields.
Moved fields a bit to get bool fields after each other (better alignment)
Link view/derived table fields to a real table to check turning the table record to null row.
Item_direct_view_ref wrapper now checks if table is turned to null row.
The bug prevented acceptance of UNION queries whose non-first select
clauses contained join expressions with degenerated single-table nests
as valid queries.
The bug was introduced into mysql-5.5 code line by the patch for
bug 33204.
As part of derived tables redesign, values for VIEW_ALGORITHM_MERGE and VIEW_ALGORITHM_TMPTABLE have changed from (former values 1 rsp 2 , new values 5 rsp 9).
This lead to the problem that views, created with version 5.2 or earlier would not work in all situations (e.g "SHOW CREATE VIEW"), or with mysqldump.
The fix is to restore backward compatibility for the from file, and convert algorithm={1,2} in the frm to {5,9} when reading .frm from disk, and store backward compatible values when writing from to disk.
Also allow processing correct processing for "invalid" .frms created with MariaDB 5.3/5.5 GA releases (where algorithm stored in memory matched the one stored in frm).
When a view/derived table is converted from merged to materialized the
items from the used_item lists are substituted for items referring to
the fields of the result of the materialization. The problem appeared
with queries employing natural joins. Since the resolution of a natural
join was performed only once the used_item list formed at the second
execution of the query lacked the references to the fields that were
used only in the equality predicates generated for the natural join.
- When doing join optimization, pre-sort the tables so that they mimic the execution
order we've had with 'semijoin=off'.
- That way, we will not get regressions when there are two query plans (the old and the
new) that have indentical costs but different execution times (because of factors that
the optimizer was not able to take into account).
