Problem:
Queries like this showed performance degratation in 10.4 over 10.3:
SELECT temporal_literal FROM t1;
SELECT temporal_literal + 1 FROM t1;
SELECT COUNT(*) FROM t1 WHERE temporal_column = temporal_literal;
SELECT COUNT(*) FROM t1 WHERE temporal_column = string_literal;
Fix:
Replacing the universal member "MYSQL_TIME cached_time" in
Item_temporal_literal to data type specific containers:
- Date in Item_date_literal
- Time in Item_time_literal
- Datetime in Item_datetime_literal
This restores the performance, and make it even better in some cases.
See benchmark results in MDEV.
Also, this change makes futher separations of Date, Time, Datetime
from each other, which will make it possible not to derive them from
a too heavy (40 bytes) MYSQL_TIME, and replace them to smaller data
type specific containers.
Diagnostics_area::sql_errno upon query from I_S with LIMIT ROWS EXAMINED
open_normal_and_derived_table() fails because the query was already killed
as rows examined by the query are more than the limit. However, this isn't a
real error.
Fix: Check if there is actually an error before calling thd->sql_errno()
and later send a warning in handle_select() if no real error.
- Adding optional qualifiers to data types:
CREATE TABLE t1 (a schema.DATE);
Qualifiers now work only for three pre-defined schemas:
mariadb_schema
oracle_schema
maxdb_schema
These schemas are virtual (hard-coded) for now, but may turn into real
databases on disk in the future.
- mariadb_schema.TYPE now always resolves to a true MariaDB data
type TYPE without sql_mode specific translations.
- oracle_schema.DATE translates to MariaDB DATETIME.
- maxdb_schema.TIMESTAMP translates to MariaDB DATETIME.
- Fixing SHOW CREATE TABLE to use a qualifier for a data type TYPE
if the current sql_mode translates TYPE to something else.
The above changes fix the reported problem, so this script:
SET sql_mode=ORACLE;
CREATE TABLE t2 AS SELECT mariadb_date_column FROM t1;
is now replicated as:
SET sql_mode=ORACLE;
CREATE TABLE t2 (mariadb_date_column mariadb_schema.DATE);
and the slave can unambiguously treat DATE as the true MariaDB DATE
without ORACLE specific translation to DATETIME.
Similar,
SET sql_mode=MAXDB;
CREATE TABLE t2 AS SELECT mariadb_timestamp_column FROM t1;
is now replicated as:
SET sql_mode=MAXDB;
CREATE TABLE t2 (mariadb_timestamp_column mariadb_schema.TIMESTAMP);
so the slave treats TIMESTAMP as the true MariaDB TIMESTAMP
without MAXDB specific translation to DATETIME.
In case of NATURAL JOIN / USING mark all field (one table can not be opened
in any case so optimisation does not worth it).
IMHO table should be checked for used fields and filled after prepare,
when we will fave whole info about used fields but it is too big change
for a bugfix. Which will be made later by Serg patch
The code in fill_schema_schemata() did not take into account that
make_db_list() can leave empty db_names if the requested database
name was too long, so the call for db_names.at(0) crashed on assert.
- Moving the code testing if the database directory exists
into a separate function verify_database_directory_exists()
- Modifying the test to check if db_names is not empty
(Variant #2 of the patch, which keeps the sp_head object inside the
MEM_ROOT that sp_head object owns)
(10.3 requires extra work due to sp_package, will commit a separate
patch for it)
sp_head::operator new() and operator delete() were dereferencing sp_head*
pointers to memory that didn't hold a valid sp_head object (it was
not created/already destroyed).
This caused UBSan to crash when looking up type information.
Fixed by providing static sp_head::create() and sp_head::destroy() methods.
(Variant #2 of the patch, which keeps the sp_head object inside the
MEM_ROOT that sp_head object owns)
(10.3 version of the fix, with handling for class sp_package)
sp_head::operator new() and operator delete() were dereferencing sp_head*
pointers to memory that didn't hold a valid sp_head object (it was
not created/already destroyed).
This caused UBSan to crash when looking up type information.
Fixed by providing static sp_head::create() and sp_head::destroy() methods.
PR#1127: Fix is_check_constraints.result to be compatibile with 10.3
The patch is done according to the original patch for MDEV-14474
1edd09c325 and not one which is merged on server
d526679efd.
This patch includes:
- Rename from `is_check_constraint` to `is_check_constraints` to tests
and results
- Per review, change the order of fields in IS check_constraints table by adding
the column `table_name` before `constraint_name`. According to the standard
2006 there is no `table_name` column.
- Original patch and one in `10.3` supports embedded server this patch doesn't
support. After the merge `10.3` will not support also.
- Don't use patch c8b8b01b61 to change the length of `CHECK_CLAUSE` field
PR#1150: MDEV-18440: Information_schema.check_constraints possible data leak
This patch is extension of PR 1127 and includes:
- Check for table grants
- Additional test according to the MDEV specification
Signed-off-by: Vicențiu Ciorbaru <vicentiu@mariadb.org>
PR#1127: Fix is_check_constraints.result to be compatibile with 10.3
The patch is done according to the original patch for MDEV-14474
1edd09c325 and not one which is merged on server
d526679efd.
This patch includes:
- Rename from `is_check_constraint` to `is_check_constraints` to tests
and results
- Per review, change the order of fields in IS check_constraints table by adding
the column `table_name` before `constraint_name`. According to the standard
2006 there is no `table_name` column.
- Original patch and one in `10.3` supports embedded server this patch doesn't
support. After the merge `10.3` will not support also.
- Don't use patch c8b8b01b61 to change the length of `CHECK_CLAUSE` field
PR#1150: MDEV-18440: Information_schema.check_constraints possible data leak
This patch is extension of PR 1127 and includes:
- Check for table grants
- Additional test according to the MDEV specification
Basicaly it's an uninitialized read. 165 is 0xa5 which comes from TRASH_ALLOC()
Fix by calling a class ctor which initializes problematic
TMP_TABLE_PARAM::force_copy_fields field
read_statistics_for_tables_if_needed
Regression after 279a907, read_statistics_for_tables_if_needed() was
called after open_normal_and_derived_tables() failure.
Fixed by moving read_statistics_for_tables() call to a branch of
get_schema_stat_record() where result of open_normal_and_derived_tables()
is checked.
Removed THD::force_read_stats, added read_statistics_for_tables() instead.
Simplified away statistics_for_command_is_needed().
With --skip-debug-assert, DBUG_ASSERT(false) will allow execution to
continue. Hence, we will need /* fall through */ after them.
Some DBUG_ASSERT(0) were replaced by break; when the switch () statement
was followed by DBUG_ASSERT(0).
The MDEV-20265 commit e746f451d5
introduces DBUG_ASSERT(right_op == r_tbl) in
st_select_lex::add_cross_joined_table(), and that assertion would
fail in several tests that exercise joins. That commit was skipped
in this merge, and a separate fix of MDEV-20265 will be necessary in 10.4.
Fixed the following issues:
- Call info with HA_STATUS_CONST to ensure that (key_info->rec_per_key)
contains latest data
- Don't access rec_per_key if key_info->algorithm == HA_KEY_ALG_LONG_HASH
is in this case the rec_per_key points to uninitialized data
- Cleaned up code to avoid some extra 'if' and to make things more readable
- Updated test cases that used 'old' rec_per_key values
