Fixing a wrong DBUG_ASSERT.
thd->start_time and thd->start_time_sec_part cannot be 0 at the same time.
But thd->start_time can be 0 when thd->start_time_sec_part is not 0,
e.g. after:
SET timestamp=0.99;
Fixed by checking handler_stats if it's active instead of
thd->variables.log_slow_verbosity & LOG_SLOW_VERBOSITY_ENGINE.
Reviewed-by: Sergei Petrunia <sergey@mariadb.com>
Raise notes if indexes cannot be used:
- in case of data type or collation mismatch (diferent error messages).
- in case if a table field was replaced to something else
(e.g. Item_func_conv_charset) during a condition rewrite.
Added option to write warnings and notes to the slow query log for
slow queries.
New variables added/changed:
- note_verbosity, with is a set of the following options:
basic - All old notes
unusable_keys - Print warnings about keys that cannot be used
for select, delete or update.
explain - Print unusable_keys warnings for EXPLAIN querys.
The default is 'basic,explain'. This means that for old installations
the only notable new behavior is that one will get notes about
unusable keys when one does an EXPLAIN for a query. One can turn all
of all notes by either setting note_verbosity to "" or setting sql_notes=0.
- log_slow_verbosity has a new option 'warnings'. If this is set
then warnings and notes generated are printed in the slow query log
(up to log_slow_max_warnings times per statement).
- log_slow_max_warnings - Max number of warnings written to
slow query log.
Other things:
- One can now use =ALL for any 'set' variable to set all options at once.
For example using "note_verbosity=ALL" in a config file or
"SET @@note_verbosity=ALL' in SQL.
- mysqldump will in the future use @@note_verbosity=""' instead of
@sql_notes=0 to disable notes.
- Added "enum class Data_type_compatibility" and changing the return type
of all Field::can_optimize*() methods from "bool" to this new data type.
Reviewer & Co-author: Alexander Barkov <bar@mariadb.com>
- The code that prints out the notes comes mainly from Alexander
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
post-merge fixes:
* remove log_slow_queries_not_using_indexes, no need to create variables
that are deprecated since the moment of creation
* rename log_slow_query_enable->log_slow_query
no other variable uses *_enable pattern
* MDEV-29626 Assertion `self == &Sys_slow_query_log' failed in fix_log_state
* tests
Closes#2137
Thus, all these variables will be
grouped together and more logically named.
Descriptions for the old variables were updated to indicate they are
now aliases for the newly introduced variables with prefix log_slow.
log_slow_queries_not_using_indexes_filter will not be addressed
in this merge request.
log_throttle_queries_not_using_indexes seems to no longer be in use.
MTR tests are also updated to include the new variable names.
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.
