"ORDER BY" AND "LIMIT BY" CLAUSE
PROBLEM:
When a 'limit' clause is specified in a query along with
group by and order by, optimizer chooses wrong index
there by examining more number of rows than required.
However without the 'limit' clause, optimizer chooses
the right index.
ANALYSIS:
With respect to the query specified, range optimizer chooses
the first index as there is a range present ( on 'a'). Optimizer
then checks for an index which would give records in sorted
order for the 'group by' clause.
While checking chooses the second index (on 'c,b,a') based on
the 'limit' specified and the selectivity of
'quick_condition_rows' (number of rows present in the range)
in 'test_if_skip_sort_order' function.
But, it fails to consider that an order by clause on a
different column will result in scanning the entire index and
hence the estimated number of rows calculated above are
wrong (which results in choosing the second index).
FIX:
Do not enforce the 'limit' clause in the call to
'test_if_skip_sort_order' if we are creating a temporary
table. Creation of temporary table indicates that there would be
more post-processing and hence will need all the rows.
This fix is backported from 5.6. This problem is fixed in 5.6 as
part of changes for work log #5558
mysql-test/r/subselect.result:
Changes for Bug#11762052 results in the correct number of rows.
sql/sql_select.cc:
Do not pass the actual 'limit' value if 'need_tmp' is true.
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.
rpl_cant_read_event_incident:
Slave applies updates from bug11747416_32228_binlog.000001 file which
contains a CREATE TABLE t statement and an incident, when SQL thread is
running slowly IO thread may reach the incident before SQL thread
executes the create table statement.
Execute "drop table if exists t" and also perform a RESET MASTER to
clean slave binary logs.
rpl_bug41902:
Error "MYSQL_BIN_LOG::purge_logs was called with file
./master-bin.000001 not listed in the index." suppression is not
considering windows path, there is ".\master-bin.000001".
Changed suppression to: "MYSQL_BIN_LOG::purge_logs was called with file
..master-bin.000001 not listed in the index", to match ".\" and "./".
Now when a table is dropped the statistics on the table is removed
from the statistical tables. If the table is altered in such a way
that a column is dropped or the type of the column is changed then
statistics on the column is removed from the table column_stat.
It also triggers removal of the statistics on the indexes who use
this column as its component.
Added procedures that changes the names of the tables or columns
in the statistical tables for.
These procedures are used when tables/columns are renamed.
Also partly re-factored the code that introduced the persistent
statistical tables.
Added test cases into statistics.test to cover the new code.
- InnoDB now returns handler specific HA_WRONG_CREATE_OPTION instead of MySQL specific ER_ILLEGAL_HA_CREATE_OPTION
- This changes the user level error message from "Unknown error" to "Wrong create options"
mysql-test/r/lowercase_table2.result:
Updated result file
mysql-test/r/partition_innodb_plugin.result:
Updated to new error message
mysql-test/r/partition_open_files_limit.result:
Updated result file
mysql-test/r/row-checksum-old.result:
Updated to new error message
mysql-test/r/row-checksum.result:
Updated to new error message
mysql-test/r/symlink.result:
Updated result file
mysql-test/suite/innodb/r/innodb-create-options.result:
Updated to new error message
mysql-test/suite/innodb/r/innodb-zip.result:
Updated to new error message
mysql-test/suite/innodb/r/innodb.result:
Updated to new error message
storage/innobase/handler/ha_innodb.cc:
Return HA_WRONG_CREATE_OPTION instead of ER_ILLEGAL_HA_CREATE_OPTION
This gives more clear and OS indepedent error messages
storage/xtradb/handler/ha_innodb.cc:
Return HA_WRONG_CREATE_OPTION instead of ER_ILLEGAL_HA_CREATE_OPTION
This gives more clear and OS indepedent error messages
This is a followup patch for the bug enabling the test
i_binlog.binlog_mysqlbinlog_file_write.test
this was disabled in mysql trunk and mysql 5.5 as in the release
build mysqlbinlog was not debug compiled whereas the mysqld was.
Since have_debug.inc script checks only for mysqld to be debug
compiled, the test was not being skipped on release builds.
We resolve this problem by creating a new inc file
mysqlbinlog_have_debug.inc which checks exclusively for mysqlbinlog
to be debug compiled. if not it skips the test.
mysql-test/include/mysqlbinlog_have_debug.inc:
new inc file to check if mysqlbinlog is debug compiled.
- Fix the year in Monty Program Ab copyrights in the new files.
- Fix permissions handling so that SHOW EXPLAIN's handling is the
same as SHOW PROCESSLIST's.
1. Clear text password client plugin disabled by default.
2. Added an environment variable LIBMYSQL_ENABLE_CLEARTEXT_PLUGIN, that
when set to something starting with '1', 'Y' or 'y' will enable the clear
text
plugin for all connections.
3. Added a new mysql_options() option : MYSQL_ENABLE_CLEARTEXT_PLUGIN
that takes an my_bool argument. When the value of the argument is non-zero
the clear text plugin is enabled for this connection only.
4. Added an enable-cleartext-plugin config file option that takes a numeric
argument. If the numeric value of the numeric argument is non-zero the
clear
text plugin is enabled for the connection
5. Added a boolean command line option "--enable_cleartext_plugin" to
mysql, mysqlslap and mysqladmin. When specified it will call mysql_options
with the effect of #3
6. Added a new CLEARTEXT option to the connect command in mysqltest.
When specified it will enable the cleartext plugin for usage.
7. Added test cases and updated existing ones that need the clear text
plugin.
executing
The problem is that mysql lacks information about the objects a view
depends on so it can't dump views and tables in the proper order.
Thus it needs to create "stand-in" myisam tables for each view while
dumping the tables that it later drops and replaces with the actual view
view definition.
But since views can have much more columns than an actual table creating
these stand-in tables may be problematic.
There's no way to portably find out how many columns an mysiam table
can have. It's a complicated formula depending on internal server constants.
Thus we can't have a reliable error check without repeating the logic and
the formula inside mysqldump.
1. Changed the type of the columns of the stand-in tables mysqldump
makes to satisfy view dependencies from the original type to smallint
to save on row space.
2. Added a warning on the mysqldump's standard error for a possible
problems replaying the dump file if the columns of a view exceed 1000.
3. Added a test case.
Print the warning(note):
YEAR(x) is deprecated and will be removed in a future release. Please use YEAR(4) instead
on "CREATE TABLE ... YEAR(x)" or "ALTER TABLE MODIFY ... YEAR(x)", where x != 4
- Better error messages
This fixes that one again can run the test systems with many threads without having to increase fs.aio-max-nr.
mysql-test/include/mtr_check.sql:
Ignore the INNODB_USE_NATIVE_AIO variable (may change during execution)
mysql-test/mysql-test-run.pl:
Ignore warnings for failure to setup AIO
storage/innobase/os/os0file.c:
Continue without AIO even if we can't allocate resources for AIO
storage/xtradb/os/os0file.c:
Continue without AIO even if we can't allocate resources for AIO
storage/xtradb/srv/srv0start.c:
Give an error message (instead of core dump) if AIO can't be initialized
TABLE_LIST::check_single_table made aware about fact that now if table attached to a merged view it can be (unopened) temporary table
(in 5.2 it was always leaf table or non (in case of several tables)).
mysql.column_stat, mysql.table_stat for the type DECIMAL(12,4).
When cached the values from these columns are multiplied by factor 10^5
and stored as ulong numbers now.
Keep track of how many pending XIDs (transactions that are prepared in
storage engine and written into binlog, but not yet durably committed
on disk in the engine) there are in each binlog.
When the count of one binlog drops to zero, write a new binlog checkpoint
event, telling which is the oldest binlog with pending XIDs.
When doing XA recovery after a crash, check the last binlog checkpoint
event, and scan all binlog files from that point onwards for XIDs that
must be committed if found in prepared state inside engine.
Remove the code in binlog rotation that waits for all prepared XIDs to
be committed before writing a new binlog file (this is no longer necessary
when recovery can scan multiple binlog files).
Add function to replace arbitrary event with dummy event.
Add code which uses this to fix the bug that enabling row_annotate events
on the master breaks slaves which do not request such events.
Add that slaves set a variable @mariadb_slave_capability to inform the
master in a robust way about which events it can, and cannot, handle.
Add tests.
the new file is fully synced to disk and binlog index. This fixes a window
where a crash would leave next server restart unable to detect that a crash
occured, causing recovery to fail.
We set correct cmp_context during preparation to avoid changing it later by Item_field::equal_fields_propagator.
(see mysql bugs #57135#57692 during merging)
