MySQL-Connector-Net casts SEQ_IN_INDEX to uint and will
raise an exception if the type is a System.Int64.
As we don't support a huge number of multi-columns in
an index reducing to a uint is sufficient to represent
all values and maintain compatibility with MySQL-Connector-Net.
This matches the type (uint) returned by MySQL-8.3 and 8.0.
Reviewer: Alexander Barkov <bar@mariadb.com>
Two new information_schema views are added:
* PERIOD table -- columns TABLE_CATALOG, TABLE_SCHEMA, TABLE_NAME,
PERIOD_NAME, START_COLUMN_NAME, END_COLUMN_NAME.
* KEY_PERIOD_USAGE -- works similar to KEY_COLUMN_USAGE, but for periods.
Columns CONSTRAINT_CATALOG, CONSTRAINT_SCHEMA, CONSTRAINT_NAME,
TABLE_CATALOG, TABLE_SCHEMA, TABLE_NAME, PERIOD_NAME
Two new columns are added to the COLUMNS view:
IS_SYSTEM_TIME_PERIOD_START, IS_SYSTEM_TIME_PERIOD_END - contain YES/NO.
MDEV-32441 SENT_ROWS shows random wrong values when stored function
is selected.
MDEV-32281 EXAMINED_ROWS is not populated in
information_schema.processlist upon SELECT.
Added ROWS_SENT to information_schema.processlist
This is to have the same information as Percona server (SENT_ROWS)
To ensure that information_schema.processlist has correct values for
sent_rows and examined_rows I introduced two new variables to hold the
total counts so far. This was needed as stored functions and stored
procedures will reset the normal counters to be able to count rows for
each statement individually for slow query log.
Other things:
- Selects with functions shows in processlist the total examined_rows
and sent_rows by the main statement and all functions.
- Stored procedures shows in processlist examined_rows and sent_rows
per stored procedure statement.
- Fixed some double accounting for sent_rows and examined_rows.
- HANDLER operations now also supports send_rows and examined_rows.
- Display sizes for MEMORY_USED, MAX_MEMORY_USED, EXAMINED_ROWS and
QUERY_ID in information_schema.processlist changed to 10 characters.
- EXAMINED_ROWS and SENT_ROWS changed to bigint.
- INSERT RETURNING and DELETE RETURNING now updates SENT_ROWS.
- As thd is always up to date with examined_rows, we do not need
to handle examined row counting for unions or filesort.
- I renamed SORT_INFO::examined_rows to m_examined_rows to ensure that
we don't get bugs in merges that tries to use examined_rows.
- Removed calls of type "thd->set_examined_row_count(0)" as they are
not needed anymore.
- Removed JOIN::join_examined_rows
- Removed not used functions:
THD::set_examined_row_count()
- Made inline some functions that where called for each row.
standard table KEY_COLUMN_USAGE should only show keys where
a user has some privileges on every column of the key
standard table TABLE_CONSTRAINTS should show tables where
a user has any non-SELECT privilege on the table or on any column
of the table
standard table REFERENTIAL_CONSTRAINTS is defined in terms of
TABLE_CONSTRAINTS, so the same rule applies. If the user
has no rights to see the REFERENCED_TABLE_NAME value, it should be NULL
SHOW INDEX (and STATISTICS table) is non-standard, but it seems
reasonable to use the same logic as for KEY_COLUMN_USAGE.
This includes all test changes from
"Changing all cost calculation to be given in milliseconds"
and forwards.
Some of the things that caused changes in the result files:
- As part of fixing tests, I added 'echo' to some comments to be able to
easier find out where things where wrong.
- MATERIALIZED has now a higher cost compared to X than before. Because
of this some MATERIALIZED types have changed to DEPENDEND SUBQUERY.
- Some test cases that required MATERIALIZED to repeat a bug was
changed by adding more rows to force MATERIALIZED to happen.
- 'Filtered' in SHOW EXPLAIN has in many case changed from 100.00 to
something smaller. This is because now filtered also takes into
account the smallest possible ref access and filters, even if they
where not used. Another reason for 'Filtered' being smaller is that
we now also take into account implicit filtering done for subqueries
using FIRSTMATCH.
(main.subselect_no_exists_to_in)
This is caluculated in best_access_path() and stored in records_out.
- Table orders has changed because more accurate costs.
- 'index' and 'ALL' for small tables has changed to use 'range' or
'ref' because of optimizer_scan_setup_cost.
- index can be changed to 'range' as 'range' optimizer assumes we don't
have to read the blocks from disk that range optimizer has already read.
This can be confusing in the case where there is no obvious where clause
but instead there is a hidden 'key_column > NULL' added by the optimizer.
(main.subselect_no_exists_to_in)
- Scan on primary clustered key does not report 'Using Index' anymore
(It's a table scan, not an index scan).
- For derived tables, the number of rows is now 100 instead of 2,
which can be seen in EXPLAIN.
- More tests have "Using index for group by" as the cost of this
optimization is now more correct (lower).
- A primary key could be preferred for a normal key, even if it would
access more rows, as it's faster to do 1 lokoup and 3 'index_next' on a
clustered primary key than one lookup trough a secondary.
(main.stat_tables_innodb)
Notes:
- There was a 4.7% more calls to best_extension_by_limited_search() in
the main.greedy_optimizer test. However examining the test results
it looked that the plans where slightly better (eq_ref where more
chained together) so I assume this is ok.
- I have verified a few test cases where there was notable/unexpected
changes in the plan and in all cases the new optimizer plans where
faster. (main.greedy_optimizer and some others)
- Added one neutral and 22 tailored (language specific) collations based on
Unicode Collation Algorithm version 14.0.0.
Collations were added for Unicode character sets
utf8mb3, utf8mb4, ucs2, utf16, utf32.
Every tailoring was added with four accent and case
sensitivity flag combinations, e.g:
* utf8mb4_uca1400_swedish_as_cs
* utf8mb4_uca1400_swedish_as_ci
* utf8mb4_uca1400_swedish_ai_cs
* utf8mb4_uca1400_swedish_ai_ci
and their _nopad_ variants:
* utf8mb4_uca1400_swedish_nopad_as_cs
* utf8mb4_uca1400_swedish_nopad_as_ci
* utf8mb4_uca1400_swedish_nopad_ai_cs
* utf8mb4_uca1400_swedish_nopad_ai_ci
- Introducing a conception of contextually typed named collations:
CREATE DATABASE db1 CHARACTER SET utf8mb4;
CREATE TABLE db1.t1 (a CHAR(10) COLLATE uca1400_as_ci);
The idea is that there is no a need to specify the character set prefix
in the new collation names. It's enough to type just the suffix
"uca1400_as_ci". The character set is taken from the context.
In the above example script the context character set is utf8mb4.
So the CREATE TABLE will make a column with the collation
utf8mb4_uca1400_as_ci.
Short collations names can be used in any parts of the SQL syntax
where the COLLATE clause is understood.
- New collations are displayed only one time
(without character set combinations) by these statements:
SELECT * FROM INFORMATION_SCHEMA.COLLATIONS;
SHOW COLLATION;
For example, all these collations:
- utf8mb3_uca1400_swedish_as_ci
- utf8mb4_uca1400_swedish_as_ci
- ucs2_uca1400_swedish_as_ci
- utf16_uca1400_swedish_as_ci
- utf32_uca1400_swedish_as_ci
have just one entry in INFORMATION_SCHEMA.COLLATIONS and SHOW COLLATION,
with COLLATION_NAME equal to "uca1400_swedish_as_ci", which is the suffix
without the character set name:
SELECT COLLATION_NAME FROM INFORMATION_SCHEMA.COLLATIONS
WHERE COLLATION_NAME LIKE '%uca1400_swedish_as_ci';
+-----------------------+
| COLLATION_NAME |
+-----------------------+
| uca1400_swedish_as_ci |
+-----------------------+
Note, the behaviour of old collations did not change.
Non-unicode collations (e.g. latin1_swedish_ci) and
old UCA-4.0.0 collations (e.g. utf8mb4_unicode_ci)
are still displayed with the character set prefix, as before.
- The structure of the table INFORMATION_SCHEMA.COLLATIONS was changed.
The NOT NULL constraint was removed from these columns:
- CHARACTER_SET_NAME
- ID
- IS_DEFAULT
and from the corresponding columns in SHOW COLLATION.
For example:
SELECT COLLATION_NAME, CHARACTER_SET_NAME, ID, IS_DEFAULT
FROM INFORMATION_SCHEMA.COLLATIONS
WHERE COLLATION_NAME LIKE '%uca1400_swedish_as_ci';
+-----------------------+--------------------+------+------------+
| COLLATION_NAME | CHARACTER_SET_NAME | ID | IS_DEFAULT |
+-----------------------+--------------------+------+------------+
| uca1400_swedish_as_ci | NULL | NULL | NULL |
+-----------------------+--------------------+------+------------+
The NULL value in these columns now means that the collation
is applicable to multiple character sets.
The behavioir of old collations did not change.
Make sure your client programs can handle NULL values in these columns.
- The structure of the table
INFORMATION_SCHEMA.COLLATION_CHARACTER_SET_APPLICABILITY was changed.
Three new NOT NULL columns were added:
- FULL_COLLATION_NAME
- ID
- IS_DEFAULT
New collations have multiple entries in COLLATION_CHARACTER_SET_APPLICABILITY.
The column COLLATION_NAME contains the collation name without the character
set prefix. The column FULL_COLLATION_NAME contains the collation name with
the character set prefix.
Old collations have full collation name in both FULL_COLLATION_NAME and
COLLATION_NAME.
SELECT COLLATION_NAME, FULL_COLLATION_NAME, CHARACTER_SET_NAME, ID, IS_DEFAULT
FROM INFORMATION_SCHEMA.COLLATION_CHARACTER_SET_APPLICABILITY
WHERE FULL_COLLATION_NAME RLIKE '^(utf8mb4|latin1).*swedish.*ci$';
+-----------------------------+-------------------------------------+--------------------+------+------------+
| COLLATION_NAME | FULL_COLLATION_NAME | CHARACTER_SET_NAME | ID | IS_DEFAULT |
+-----------------------------+-------------------------------------+--------------------+------+------------+
| latin1_swedish_ci | latin1_swedish_ci | latin1 | 8 | Yes |
| latin1_swedish_nopad_ci | latin1_swedish_nopad_ci | latin1 | 1032 | |
| utf8mb4_swedish_ci | utf8mb4_swedish_ci | utf8mb4 | 232 | |
| uca1400_swedish_ai_ci | utf8mb4_uca1400_swedish_ai_ci | utf8mb4 | 2368 | |
| uca1400_swedish_as_ci | utf8mb4_uca1400_swedish_as_ci | utf8mb4 | 2370 | |
| uca1400_swedish_nopad_ai_ci | utf8mb4_uca1400_swedish_nopad_ai_ci | utf8mb4 | 2372 | |
| uca1400_swedish_nopad_as_ci | utf8mb4_uca1400_swedish_nopad_as_ci | utf8mb4 | 2374 | |
+-----------------------------+-------------------------------------+--------------------+------+------------+
- Other INFORMATION_SCHEMA queries:
SELECT COLLATION_NAME FROM INFORMATION_SCHEMA.COLUMNS;
SELECT COLLATION_NAME FROM INFORMATION_SCHEMA.PARAMETERS;
SELECT TABLE_COLLATION FROM INFORMATION_SCHEMA.TABLES;
SELECT DEFAULT_COLLATION_NAME FROM INFORMATION_SCHEMA.SCHEMATA;
SELECT COLLATION_NAME FROM INFORMATION_SCHEMA.ROUTINES;
SELECT COLLATION_CONNECTION FROM INFORMATION_SCHEMA.EVENTS;
SELECT DATABASE_COLLATION FROM INFORMATION_SCHEMA.EVENTS;
SELECT COLLATION_CONNECTION FROM INFORMATION_SCHEMA.ROUTINES;
SELECT DATABASE_COLLATION FROM INFORMATION_SCHEMA.ROUTINES;
SELECT COLLATION_CONNECTION FROM INFORMATION_SCHEMA.TRIGGERS;
SELECT DATABASE_COLLATION FROM INFORMATION_SCHEMA.TRIGGERS;
SELECT COLLATION_CONNECTION FROM INFORMATION_SCHEMA.VIEWS;
display full collation names, including character sets prefix,
for all collations, including new collations.
Corresponding SHOW commands also display full collation names
in collation related columns:
SHOW CREATE TABLE t1;
SHOW CREATE DATABASE db1;
SHOW TABLE STATUS;
SHOW CREATE FUNCTION f1;
SHOW CREATE PROCEDURE p1;
SHOW CREATE EVENT ev1;
SHOW CREATE TRIGGER tr1;
SHOW CREATE VIEW;
These INFORMATION_SCHEMA queries and SHOW statements may change in
the future, to display show collation names.
The 10.5 version of the patch.
Removing DEFAULT from INFORMATION_SCHEMA columns.
DEFAULT in read-only tables is rather meaningless.
Upgrade should go smoothly.
Also fixes:
MDEV-20254 Problems with EMPTY_STRING_IS_NULL and I_S tables
Removing DEFAULT from INFORMATION_SCHEMA columns.
DEFAULT in read-only tables is rather meaningless.
Upgrade should go smoothly.
Also fixes:
MDEV-20254 Problems with EMPTY_STRING_IS_NULL and I_S tables
Add KEYWORDS table and SQL_FUNCTIONS table to INFORMATION_SCHEMA.
This commits needs some minor changes when propagated upwards
(e.g. func_array in item_create.cc has a termination element that
doesn't exist in later versions of MariaDB)
This patch changes the main name of 3 byte character set from utf8 to
utf8mb3. New old_mode UTF8_IS_UTF8MB3 is added and set TRUE by default,
so that utf8 would mean utf8mb3. If not set, utf8 would mean utf8mb4.
This feature adds the functionality of ignorability for indexes.
Indexes are not ignored be default.
To control index ignorability explicitly for a new index,
use IGNORE or NOT IGNORE as part of the index definition for
CREATE TABLE, CREATE INDEX, or ALTER TABLE.
Primary keys (explicit or implicit) cannot be made ignorable.
The table INFORMATION_SCHEMA.STATISTICS get a new column named IGNORED that
would store whether an index needs to be ignored or not.
This task involves the implementation for the optimizer trace.
This feature produces a trace for any SELECT/UPDATE/DELETE/,
which contains information about decisions taken by the optimizer during
the optimization phase (choice of table access method, various costs,
transformations, etc). This feature would help to tell why some decisions were
taken by the optimizer and why some were rejected.
Trace is session-local, controlled by the @@optimizer_trace variable.
To enable optimizer trace we need to write:
set @@optimizer_trace variable= 'enabled=on';
To display the trace one can run:
SELECT trace FROM INFORMATION_SCHEMA.OPTIMIZER_TRACE;
This task also involves:
MDEV-18489: Limit the memory used by the optimizer trace
introduces a switch optimizer_trace_max_mem_size which limits
the memory used by the optimizer trace. This was implemented by
Sergei Petrunia.
