This was done to get more information about where time is spent.
Now we can get proper timing for time spent in commit, rollback,
binlog write etc.
Following stages was added:
- Commit
- Commit_implicit
- Rollback
- Rollback implicit
- Binlog write
- Init for update
- This is used instead of "Init" for insert, update and delete.
- Staring cleanup
Following stages where changed:
- "Unlocking tables" stage reset stage to previous stage at end
- "binlog write" stage resets stage to previous stage at end
- "end" -> "end of update loop"
- "cleaning up" -> "Reset for next command"
- Added stage_searching_rows_for_update when searching for rows
to be deleted.
Other things:
- Renamed all stages to start with big letter (before there was no
consitency)
- Increased performance_schema_max_stage_classes from 150 to 160.
- Most of the test changes in performance schema comes from renaming of
stages.
- Removed duplicate output of variables and inital state in a lot of
performance schema tests.
This was done to make it easier to change a default value for a
performance variable without affecting all tests.
- Added start_server_variables.test to check configuration
- Removed some duplicate "closing tables" stages
- Updated position for "stage_init_update" and "stage_updating" for
delete, insert and update to be just before update loop (for more
exact timing).
- Don't set "Checking permissions" twice in a row.
- Remove stage_end stage from creating views (not done for create table
either).
- Updated default performance history size from 10 to 20 because of new
stages
- Ensure that ps_enabled is correct (to be used in a later patch)
As a result of this merge the code for the following tasks appears in 10.3:
- MDEV-12172 Implement tables specified by table value constructors
- MDEV-12176 Transform [NOT] IN predicate with long list of values INTO
[NOT] IN subquery.
Storage engine independent support for column compression.
TINYBLOB, BLOB, MEDIUMBLOB, LONGBLOB, TINYTEXT, TEXT, MEDIUMTEXT, LONGTEXT,
VARCHAR and VARBINARY columns can be compressed.
New COMPRESSED column attribute added:
COMPRESSED[=<compression_method>]
System variables added:
column_compression_threshold
column_compression_zlib_level
column_compression_zlib_strategy
column_compression_zlib_wrap
Status variables added:
Column_compressions
Column_decompressions
Limitations:
- the only supported method currently is zlib
- CSV storage engine stores data uncompressed on-disk even if COMPRESSED
attribute is present
- it is not possible to create indexes over compressed columns.
For running the Galera tests, the variable my_disable_leak_check
was set to true in order to avoid assertions due to memory leaks
at shutdown.
Some adjustments due to MDEV-13625 (merge InnoDB tests from MySQL 5.6)
were performed. The most notable behaviour changes from 10.0 and 10.1
are the following:
* innodb.innodb-table-online: adjustments for the DROP COLUMN
behaviour change (MDEV-11114, MDEV-13613)
* innodb.innodb-index-online-fk: the removal of a (1,NULL) record
from the result; originally removed in MySQL 5.7 in the
Oracle Bug #16244691 fix
377774689b
* innodb.create-index-debug: disabled due to MDEV-13680
(the MySQL Bug #77497 fix was not merged from 5.6 to 5.7.10)
* innodb.innodb-alter-autoinc: MariaDB 10.2 behaves like MySQL 5.6/5.7,
while MariaDB 10.0 and 10.1 assign different values when
auto_increment_increment or auto_increment_offset are used.
Also MySQL 5.6/5.7 exhibit different behaviour between
LGORITHM=INPLACE and ALGORITHM=COPY, so something needs to be tested
and fixed in both MariaDB 10.0 and 10.2.
* innodb.innodb-wl5980-alter: disabled because it would trigger an
InnoDB assertion failure (MDEV-13668 may need additional effort in 10.2)
- make re-bootstrap run with all extra options, not only InnoDB ones
- re-use previously created bootstrap.sql
- add --console
- fix debian patch to keep it applicable
This fixes MDEV-7742 and MDEV-8305 (Allow user to specify if stored
procedures should be logged in the slow and general log)
New functionality:
- Added new variables log_slow_disable_statements and log_disable_statements
that can be used to disable logging of certain queries to slow and
general log. Currently supported options are 'admin', 'call', 'slave'
and 'sp'.
Defaults are as before. Only 'sp' (stored procedure statements) is
disabled for slow and general_log.
- Slow log to files now includes the following new information:
- When logging stored procedure statements the name of stored
procedure is logged.
- Number of created tmp_tables, tmp_disk_tables and the space used
by temporary tables.
- When logging 'call', the logged status now contains the sum of all
included statements. Before only 'time' was correct.
- Added filsort_priority_queue as an option for log_slow_filter (this
variable existed before, but was not exposed)
- Added support for BIT types in my_getopt()
Mapped some old variables to bitmaps (old variables can still be used)
- Variable 'log_queries_not_using_indexes' is mapped to
log_slow_filter='not_using_index'
- Variable 'log_slow_slave_statements' is mapped to
log_slow_disabled_statements='slave'
- Variable 'log_slow_admin_statements' is mapped to
log_slow_disabled_statements='admin'
- All the above variables are changed to session variables from global
variables
Other things:
- Simplified LOGGER::log_command. We don't need to check for super if
OPTION_LOG_OFF is set as this flag can only be set if one is a super
user.
- Removed some setting of enable_slow_log as it's guaranteed to be set by
mysql_parse()
- mysql_admin_table() now sets thd->enable_slow_log
- Added prepare_logs_for_admin_command() to reset thd->enable_slow_log if
needed.
- Added new functions to store, restore and add slow query status
- Added new functions to store and restore query start time
- Reorganized Sub_statement_state according to types
- Added code in dispatch_command() to ensure that
thd->reset_for_next_command() is always called for a query.
- Added thd->last_sql_command to simplify checking of what was the type
of the last command. Needed when logging to slow log as lex->sql_command
may have changed before slow logging is called.
- Moved QPLAN_TMP_... to where status for tmp tables are updated
- Added new THD variable, affected_rows, to be able to correctly log
number of affected rows to slow log.
accept proxy protocol header from client connections.
The new server variable 'proxy_protocol_networks' contains list
of networks from which proxy header is accepted.
"Optimization for equi-joins of derived tables with GROUP BY"
should be considered rather as a 'proof of concept'.
The task itself is targeted at an optimization that employs re-writing
equi-joins with grouping derived tables / views into lateral
derived tables. Here's an example of such transformation:
select t1.a,t.max,t.min
from t1 [left] join
(select a, max(t2.b) max, min(t2.b) min from t2
group by t2.a) as t
on t1.a=t.a;
=>
select t1.a,tl.max,tl.min
from t1 [left] join
lateral (select a, max(t2.b) max, min(t2.b) min from t2
where t1.a=t2.a) as t
on 1=1;
The transformation pushes the equi-join condition t1.a=t.a into the
derived table making it dependent on table t1. It means that for
every row from t1 a new derived table must be filled out. However
the size of any of these derived tables is just a fraction of the
original derived table t. One could say that transformation 'splits'
the rows used for the GROUP BY operation into separate groups
performing aggregation for a group only in the case when there is
a match for the current row of t1.
Apparently the transformation may produce a query with a better
performance only in the case when
- the GROUP BY list refers only to fields returned by the derived table
- there is an index I on one of the tables T used in FROM list of
the specification of the derived table whose prefix covers the
the fields from the proper beginning of the GROUP BY list or
fields that are equal to those fields.
Whether the result of the re-writing can be executed faster depends
on many factors:
- the size of the original derived table
- the size of the table T
- whether the index I is clustering for table T
- whether the index I fully covers the GROUP BY list.
This patch only tries to improve the chosen execution plan using
this transformation. It tries to do it only when the chosen
plan reaches the derived table by a key whose prefix covers
all the fields of the derived table produced by the fields of
the table T from the GROUP BY list.
The code of the patch does not evaluates the cost of the improved
plan. If certain conditions are met the transformation is applied.
- Added variable tmp_disk_table_size
- Added variable tmp_memory_table_size as an alias for tmp_table_size
- Changed internal variable tmp_table_size to tmp_memory_table_size
- create_info.data_file_length is now set with tmp_disk_table_size
- Fixed that Aria doesn't reset max_data_file_length for internal tables
- Added status flag if table is full so that we can detect this on next insert.
This ensures that the table is always 'correct', but we get the error one
row after the row that grow the table too big.
- Removed some mutex lock for internal temporary tables
sql_sequence.read_only: Show that the sequence can be read in
both read-only and read-write mode, and that the sequence remains
accessible after a server restart.
- SETVAL(sequence_name, next_value, is_used, round)
- ALTER SEQUENCE, including RESTART WITH
Other things:
- Added handler::extra() option HA_EXTRA_PREPARE_FOR_ALTER_TABLE to signal
ha_sequence() that it should allow write_row statments.
- ALTER ONLINE TABLE now works with SEQUENCE:s
Working features:
CREATE OR REPLACE [TEMPORARY] SEQUENCE [IF NOT EXISTS] name
[ INCREMENT [ BY | = ] increment ]
[ MINVALUE [=] minvalue | NO MINVALUE ]
[ MAXVALUE [=] maxvalue | NO MAXVALUE ]
[ START [ WITH | = ] start ] [ CACHE [=] cache ] [ [ NO ] CYCLE ]
ENGINE=xxx COMMENT=".."
SELECT NEXT VALUE FOR sequence_name;
SELECT NEXTVAL(sequence_name);
SELECT PREVIOUS VALUE FOR sequence_name;
SELECT LASTVAL(sequence_name);
SHOW CREATE SEQUENCE sequence_name;
SHOW CREATE TABLE sequence_name;
CREATE TABLE sequence-structure ... SEQUENCE=1
ALTER TABLE sequence RENAME TO sequence2;
RENAME TABLE sequence TO sequence2;
DROP [TEMPORARY] SEQUENCE [IF EXISTS] sequence_names
Missing features
- SETVAL(value,sequence_name), to be used with replication.
- Check replication, including checking that sequence tables are marked
not transactional.
- Check that a commit happens for NEXT VALUE that changes table data (may
already work)
- ALTER SEQUENCE. ANSI SQL version of setval.
- Share identical sequence entries to not add things twice to table list.
- testing insert/delete/update/truncate/load data
- Run and fix Alibaba sequence tests (part of mysql-test/suite/sql_sequence)
- Write documentation for NEXT VALUE / PREVIOUS_VALUE
- NEXTVAL in DEFAULT
- Ensure that NEXTVAL in DEFAULT uses database from base table
- Two NEXTVAL for same row should give same answer.
- Oracle syntax sequence_table.nextval, without any FOR or FROM.
- Sequence tables are treated as 'not read constant tables' by SELECT; Would
be better if we would have a separate list for sequence tables so that
select doesn't know about them, except if refereed to with FROM.
Other things done:
- Improved output for safemalloc backtrack
- frm_type_enum changed to Table_type
- Removed lex->is_view and replaced with lex->table_type. This allows
use to more easy check if item is view, sequence or table.
- Added table flag HA_CAN_TABLES_WITHOUT_ROLLBACK, needed for handlers
that want's to support sequences
- Added handler calls:
- engine_name(), to simplify getting engine name for partition and sequences
- update_first_row(), to be able to do efficient sequence implementations.
- Made binlog_log_row() global to be able to call it from ha_sequence.cc
- Added handler variable: row_already_logged, to be able to flag that the
changed row is already logging to replication log.
- Added CF_DB_CHANGE and CF_SCHEMA_CHANGE flags to simplify
deny_updates_if_read_only_option()
- Added sp_add_cfetch() to avoid new conflicts in sql_yacc.yy
- Moved code for add_table_options() out from sql_show.cc::show_create_table()
- Added String::append_longlong() and used it in sql_show.cc to simplify code.
- Added extra option to dd_frm_type() and ha_table_exists to indicate if
the table is a sequence. Needed by DROP SQUENCE to not drop a table.
