"#ifdef WITH_PARTITION_STORAGE_ENGINE ... #endif" appears frequently
in the Spider code base. However, there is no need to maintain such
ifdefs because Spider is disabled if the partitioning engine is disabled.
Replace
* select_lex::offset_limit
* select_lex::select_limit
* select_lex::explicit_limit
with select_lex::Lex_select_limit
The Lex_select_limit already existed with the same elements and was used in
by the yacc parser.
This commit is in preparation for FETCH FIRST implementation, as it
simplifies a lot of the code.
Additionally, the parser is simplified by making use of the stack to
return Lex_select_limit objects.
Cleanup of init_query() too. Removes explicit_limit= 0 as it's done a bit later
in init_select() with limit_params.empty()
When executing a query like "select id, 0 as const, val from ...", there are 3 columns(items) in Query->select at handlerton->create_group_by(). After that, MariaDB makes a temporary table with 2 columns. The skipped items are const item, so fixing Spider to skip const items for items at Query->select.
Change the following function for batch call instead of each partition
- store_lock
- external_lock
- start_stmt
- extra
- cond_push
- info_push
- top_table
When executing a query like "select id, 0 as const, val from ...", there are 3 columns(items) in Query->select at handlerton->create_group_by(). After that, MariaDB makes a temporary table with 2 columns. The skipped items are const item, so fixing Spider to skip const items for items at Query->select.
Add a system variable spider_slave_trx_isolation.
- spider_slave_trx_isolation
The transaction isolation level when Spider table is used by slave SQL thread.
-1 : OFF
0 : READ UNCOMMITTED
1 : READ COMMITTED
2 : REPEATABLE READ
3 : SERIALIZABLE
The default value is -1
Miscellaneous Spider typos
Add a system variable spider_slave_trx_isolation.
- spider_slave_trx_isolation
The transaction isolation level when Spider table is used by slave SQL thread.
-1 : OFF
0 : READ UNCOMMITTED
1 : READ COMMITTED
2 : REPEATABLE READ
3 : SERIALIZABLE
The default value is -1
Miscellaneous Spider typos
The SELECT with the INNER JOIN is executed with one of the two tables being
optimized as a constant table, which is pre-read. Spider nevertheless attempts
to push down the join to the data node. The crash occurs because the constant
table is excluded from the optimized query that Spider attempts to push down.
In order for Spider to be able to push down a join, the following conditions
need to be met:
- All of the tables involved in the join need to be included in the optimized
query that Spider pushes down. When any of the tables involved in the join
is a constant table, it is excluded from the optimized query that Spider
attempts to push down.
- All fields involved in the query need to be members of tables included in the
optimized query.
I fixed the problem by preventing Spider from pushing down queries that include
a field that is not a member of a table included in the optimized query. This
solution fixes the reported problem and also fixes other potential problems.
Author:
Jacob Mathew.
Reviewer:
Kentoku Shiba.
Cherry-Picked:
Commit 4885baf on branch bb-10.3-MDEV-16889
The SELECT with the INNER JOIN is executed with one of the two tables being
optimized as a constant table, which is pre-read. Spider nevertheless attempts
to push down the join to the data node. The crash occurs because the constant
table is excluded from the optimized query that Spider attempts to push down.
In order for Spider to be able to push down a join, the following conditions
need to be met:
- All of the tables involved in the join need to be included in the optimized
query that Spider pushes down. When any of the tables involved in the join
is a constant table, it is excluded from the optimized query that Spider
attempts to push down.
- All fields involved in the query need to be members of tables included in the
optimized query.
I fixed the problem by preventing Spider from pushing down queries that include
a field that is not a member of a table included in the optimized query. This
solution fixes the reported problem and also fixes other potential problems.
Author:
Jacob Mathew.
Reviewer:
Kentoku Shiba.
The problem occurred because the Spider node was incorrectly handling
timestamp values sent to and received from the data nodes.
The problem has been corrected as follows:
- Added logic to set and maintain the UTC time zone on the data nodes.
To prevent timestamp ambiguity, it is necessary for the data nodes to use
a time zone such as UTC which does not have daylight savings time.
- Removed the spider_sync_time_zone configuration variable, which did not
solve the problem and which interfered with the solution.
- Added logic to convert to the UTC time zone all timestamp values sent to
and received from the data nodes. This is done for both unique and
non-unique timestamp columns. It is done for WHERE clauses, applying to
SELECT, UPDATE and DELETE statements, and for UPDATE columns.
- Disabled Spider's use of direct update when any of the columns to update is
a timestamp column. This is necessary to prevent false duplicate key value
errors.
- Added a new test spider.timestamp to thoroughly test Spider's handling of
timestamp values.
Author:
Jacob Mathew.
Reviewer:
Kentoku Shiba.
Merged:
Commit 97cc9d3 on branch bb-10.3-MDEV-16246
The problem occurred because the Spider node was incorrectly handling
timestamp values sent to and received from the data nodes.
The problem has been corrected as follows:
- Added logic to set and maintain the UTC time zone on the data nodes.
To prevent timestamp ambiguity, it is necessary for the data nodes to use
a time zone such as UTC which does not have daylight savings time.
- Removed the spider_sync_time_zone configuration variable, which did not
solve the problem and which interfered with the solution.
- Added logic to convert to the UTC time zone all timestamp values sent to
and received from the data nodes. This is done for both unique and
non-unique timestamp columns. It is done for WHERE clauses, applying to
SELECT, UPDATE and DELETE statements, and for UPDATE columns.
- Disabled Spider's use of direct update when any of the columns to update is
a timestamp column. This is necessary to prevent false duplicate key value
errors.
- Added a new test spider.timestamp to thoroughly test Spider's handling of
timestamp values.
Author:
Jacob Mathew.
Reviewer:
Kentoku Shiba.
Cherry-Picked:
Commit 97cc9d3 on branch bb-10.3-MDEV-16246
Includes Spider patches
- 062_mariadb-10.2.0.direct_join_1and3.diff
- 063_mariadb-10.2.0.direct_join_for_single_partition.diff
- Test cases from Kentoku
Allows Spider to push full joins to the Spider engine trough the
create_group_by interface.
Other things:
- Increased MYSQL_VERSION_ID to check for 10211 (latest 10.2 version)
- Fix for const_table at calling create_group_by().
Original author: Kentoku SHIBA
