Following reasons caused mismatches:
- different handling of invalid values;
- different CAST results with fractional seconds;
- microseconds support in MariaDB;
- different algorithm of comparing temporal values;
- differences in error and warning texts and codes;
- different approach to truncating datetime values to time;
- additional collations;
- different record order for queries without ORDER BY;
- MySQL bug#66034.
More details in MDEV-369 comments.
make CMakeLists.txt to detect if the installed boost can be compiled with the
installed compile and specified set of compiler options.
Background: even sufficiently new Boost cannot be compiled with the sufficiently old gcc
in the presence of -fno-rtti
mysql_rm_table_no_locks() function was modified.
When we construct log record for the DROP TABLE, now we
look if there's a comment before the first table name and
add it to the record if so.
per-file comments:
sql/sql_table.cc
MDEV-340 Save replication comments for DROP TABLE.
comment_length() function implemented to find comments in the query,
call it in mysql_rm_table_no_locks() and use the result to form log record.
mysql-test/suite/binlog/r/binlog_drop_if_exists.result
MDEV-340 Save replication comments for DROP TABLE.
test result updated.
mysql-test/suite/binlog/t/binlog_drop_if_exists.test
MDEV-340 Save replication comments for DROP TABLE.
test case added.
Following reasons caused mismatches:
- different handling of invalid values;
- different CAST results with fractional seconds;
- microseconds support in MariaDB;
- different algorithm of comparing temporal values;
- differences in error and warning texts and codes;
- different approach to truncating datetime values to time;
- additional collations;
- different record order for queries without ORDER BY;
- MySQL bug#66034.
More details in MDEV-369 comments.
- index_merge/intersection is unable to work on GIS indexes, because:
1. index scans have no Rowid-Ordered-Retrieval property
2. When one does an index-only read over a GIS index, they do not
get the index tuple, because index only contains bounding box of the geometry.
This is why key_copy() call crashed.
This patch fixes#1, which makes the problem go away. Theoretically, it would
be nice to check #2, too, but SE API semantics is not sufficiently precise to do it.
Now partition engine adds underlying tables to the QC and ask underlying tables engine permittion to cache the query and return result of the query.
Incorrect QC cleanup in case of table registration failure fixe.
Unified interface for myisammrg & partitioned engnes for QC.
COUNT DISTINCT GROUP BY
PROBLEM:
To calculate the final result of the count(distinct(select 1))
we call 'end_send' function instead of 'end_send_group'.
'end_send' cannot be called if we have aggregate functions
that need to be evaluated.
ANALYSIS:
While evaluating for a possible loose_index_scan option for
the query, the variable 'is_agg_distinct' is set to 'false'
as the item in the distinct clause is not a field. But, we
choose loose_index_scan by not taking this into
consideration.
So, while setting the final 'select_function' to evaluate
the result, 'precomputed_group_by' is set to TRUE as in
this case loose_index_scan is chosen and we do not have
agg_distinct in the query (which is clearly wrong as we
have one).
As a result, 'end_send' function is chosen as the final
select_function instead of 'end_send_group'. The difference
between the two being, 'end_send_group' evaluates the
aggregates while 'end_send' does not. Hence the wrong result.
FIX:
The variable 'is_agg_distinct' always represents if
'loose_idnex_scan' can be chosen for aggregate_distinct
functions present in the select.
So, we check for this variable to continue with
loose_index_scan option.
sql/opt_range.cc:
Do not continue if is_agg_distinct is not set in case
of agg_distinct functions.
primary key with innodb tables
The bug was triggered if a single ALTER TABLE statement both
added and dropped indexes and ALTER TABLE failed during drop
(e.g. because the index was needed in a foreign key constraint).
In such cases, the server index information would get out of
sync with InnoDB - the added index would be present inside
InnoDB, but not in the server. This could then lead to InnoDB
error messages and/or server crashes.
The root cause is that new indexes are added before old indexes
are dropped. This means that if ALTER TABLE fails while dropping
indexes, index changes will be reverted in the server but not
inside InnoDB.
This patch fixes the problem by dropping any added indexes
if drop fails (for ALTER TABLE statements that both adds
and drops indexes).
However, this won't work if we added a primary key as this
key might not be possible to drop inside InnoDB. Therefore,
we resort to the copy algorithm if a primary key is added
by an ALTER TABLE statement that also drops an index.
In 5.6 this bug is more properly fixed by the handler interface
changes done in the scope of WL#5534 "Online ALTER".
KEY UPDATES WITH A LIMIT OF 1
Problem: The unsafety warning for statements such as
update...limit1 where pk=1 are thrown when binlog-format
= STATEMENT,despite of the fact that such statements are
actually safe. this leads to filling up of the disk space
with false warnings.
Solution: This is not a complete fix for the problem, but
prevents the disks from getting filled up. This should
therefore be regarded as a workaround. In the future this
should be overriden by server general suppress/filtering
framework. It should also be noted that another worklog is
supposed to defeat this case's artificial unsafety.
We use a warning suppression mechanism to detect warning flood,
enable the suppression, and disable this when the average
warnings/second has reduced to acceptable limits.
Activation: The supression for LIMIT unsafe statements are
activated when the last 50 warnings were logged in less
than 50 seconds.
Supression: Once activated this supression will prevent the
individual warnings to be logged in the error log, but print
the warning for every 50 warnings with the note:
"The last warning was repeated N times in last S seconds"
Noteworthy is the fact that this supression works only on the
error logs and the warnings seen by the clients will remain as
it is (i.e. one warning/ unsafe statement)
Deactivation: The supression will be deactivated once the
average # of warnings/sec have gone down to the acceptable limits.
sql/sql_class.cc:
Added code to supress warning while logging them to error-log.
