MDEV-33407 Parser support for vector indexes
The syntax is
create table t1 (... vector index (v) ...);
limitation:
* v is a binary string and NOT NULL
* only one vector index per table
* temporary tables are not supported
MDEV-33404 Engine-independent indexes: subtable method
added support for so-called "high level indexes", they are not visible
to the storage engine, implemented on the sql level. For every such
an index in a table, say, t1, the server implicitly creates a second
table named, like, t1#i#05 (where "05" is the index number in t1).
This table has a fixed structure, no frm, not accessible directly,
doesn't go into the table cache, needs no MDLs.
MDEV-33406 basic optimizer support for k-NN searches
for a query like SELECT ... ORDER BY func() optimizer will use
item_func->part_of_sortkey() to decide what keys can be used
to resolve ORDER BY.
Changing the return type of the following functions:
- CURRENT_TIMESTAMP, CURRENT_TIMESTAMP(), NOW()
- SYSDATE()
- FROM_UNIXTIME()
from DATETIME to TIMESTAMP.
Note, the old function NOW() returning DATETIME is still available
as LOCALTIMESTAMP or LOCALTIMESTAMP(), e.g.:
SELECT
LOCALTIMESTAMP, -- DATETIME
CURRENT_TIMESTAMP; -- TIMESTAMP
The change in the functions return data type fixes some problems
that occurred near a DST change:
- Problem #1
INSERT INTO t1 (timestamp_field) VALUES (CURRENT_TIMESTAMP);
INSERT INTO t1 (timestamp_field) VALUES (COALESCE(CURRENT_TIMESTAMP));
could result into two different values inserted.
- Problem #2
INSERT INTO t1 (timestamp_field) VALUES (FROM_UNIXTIME(1288477526));
INSERT INTO t1 (timestamp_field) VALUES (FROM_UNIXTIME(1288477526+3600));
could result into two equal TIMESTAMP values near a DST change.
Additional changes:
- FROM_UNIXTIME(0) now returns SQL NULL instead of '1970-01-01 00:00:00'
(assuming time_zone='+00:00')
- UNIX_TIMESTAMP('1970-01-01 00:00:00') now returns SQL NULL instead of 0
(assuming time_zone='+00:00'
These additional changes are needed for consistency with TIMESTAMP fields,
which cannot store '1970-01-01 00:00:00 +00:00'
Update `SESSION_USER()` behaviour to be comparable with `CURRENT_USER()`.
`SESSION_USER()` will return the user and host columns from `mysql.user`
used to authenticate the user when the session was created.
Historically `SESSION_USER()` was an alias of `USER()` function. The
main difference with `USER()` behaviour after this changes is that
`SESSION_USER()` now returns the host column from `mysql.user` instead of
the client host or ip.
NOTE: `SESSION_USER_IS_USER` old mode is added to make the change
backward compatible.
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.
During sql_mode=ORACLE, ignore the NOCOPY keyword in stored routine
parameters. The optimization (pass-by-reference instead of
pass-by-value) helping to avoid value copying will be done in a separate
task when needed.
Changing the alias LOCALTIME->CURRENT_TIMESTAMP to LOCALTIME->CURRENT_TIME.
This changes the return type of LOCALTIME from DATETIME to TIME,
according to the SQL Standard.
Per MDEV-20601, REPLICA should be an alias for SLAVE in SQL
statements.
Reviewed By:
============
Kristian Nielsen <knielsen@knielsen-hq.org>
Andrei Elkin <andrei.elkin@mariadb.com>
The IDENT_sys doesn't include keywords, so the function with the
keyword name can be created, but cannot be called.
Moving keywords to new rules keyword_func_sp_var_and_label and
keyword_func_sp_var_not_label so the functions with these
names are allowed.
1. WITHOUT/WITH VALIDATION may be added to EXCHANGE PARTITION or CONVERT TABLE:
alter table tp exchange partition p1 with table t with validation;
alter table tp exchange partition p1 with table t; -- same as with validation
alter table tp exchange partition p1 with table t without validation;
2. Optional THAN keyword for RANGE partitioning. Normally you type:
create table tp (a int primary key) partition by range (a) (
partition p0 values less than (100),
partition p1 values less than maxvalue);
Now you may type (PARTITION keyword is also optional):
create table tp (a int primary key) partition by range (a) (
p0 values less (100),
p1 values less maxvalue);
Changing the code handling sql_mode-dependent function DECODE():
- removing parser tokens DECODE_MARIADB_SYM and DECODE_ORACLE_SYM
- removing the DECODE() related code from sql_yacc.yy/sql_yacc_ora.yy
- adding handling of DECODE() with help of a new Create_func_func_decode
New Feature:
============
This patch extends the START SLAVE UNTIL command with options
SQL_BEFORE_GTIDS and SQL_AFTER_GTIDS to allow user control of
whether the replica stops before or after a provided GTID state. Its
syntax is:
START SLAVE UNTIL (SQL_BEFORE_GTIDS|SQL_AFTER_GTIDS)=”<gtid_list>”
When providing SQL_BEFORE_GTIDS=”<gtid_list>”, for each domain
specified in the gtid_list, the replica will execute transactions up
to the GTID found, and immediately stop processing events in that
domain (without executing the transaction of the specified GTID).
Once all domains have stopped, the replica will stop. Events
originating from domains that are not specified in the list are not
replicated.
START SLAVE UNTIL SQL_AFTER_GTIDS=”<gtid_list>” is an alias to the
default behavior of START SLAVE UNTIL master_gtid_pos=”<gtid_list>”.
That is, the replica will only execute transactions originating from
domain ids provided in the list, and will stop once all transactions
provided in the UNTIL list have all been executed.
Example:
=========
If a primary server has a binary log consisting of the following GTIDs:
0-1-1
1-1-1
0-1-2
1-1-2
0-1-3
1-1-3
If a fresh replica (i.e. one with an empty GTID position,
@@gtid_slave_pos='') is started with SQL_BEFORE_GTIDS, i.e.
START SLAVE UNTIL SQL_BEFORE_GTIDS=”1-1-2”
The resulting gtid_slave_pos of the replica will be “1-1-1”.
This is because the replica will execute only events from domain 1
until it sees the transaction with sequence number 2, and
immediately stop without executing it.
If the replica is started with SQL_AFTER_GTIDS, i.e.
START SLAVE UNTIL SQL_AFTER_GTIDS=”1-1-2”
then the resulting gtid_slave_pos of the replica will be “1-1-2”.
This is because it will only execute events from domain 1 until it
has executed the provided GTID.
Reviewed By:
============
Kristian Nielson <knielsen@knielsen-hq.org>
New Feature:
========
This feature adds a safe replacement to the
MASTER_USE_GTID=Current_Pos option for CHANGE MASTER TO as
MASTER_DEMOTE_TO_SLAVE=<bool>. The use case of Current_Pos is to
transition a master to become a slave; however, can break
replication state if the slave executes local transactions due to
actively updating gtid_current_pos with gtid_binlog_pos and
gtid_slave_pos.
MASTER_DEMOTE_TO_SLAVE changes this use case by forcing users to set
Using_Gtid=Slave_Pos and merging gtid_binlog_pos into gtid_slave_pos
once at CHANGE MASTER TO time. Note that if gtid_slave_pos is more
recent than gtid_binlog_pos (as in the case of chain replication),
the replication state should be preserved.
Additionally, deprecate the `Current_Pos` option of MASTER_USE_GTID
to suggest the safe alternative option MASTER_DEMOTE_TO_SLAVE=TRUE.
Reviewed By:
============
Andrei Elkin <andrei.elkin@mariadb.com>
Fixed after patch MDEV-26606 because root cause was same.
Analysis: m_current_row_for_warning is reset to 1 during cleanup phase of
stored procedure. When we perform a copy because some statement of procedure
created warning, this reset value is passed to push _warning().
Fix: Add a parameter in relevant functions to pass correct value of
error index and don't use m_current_row_for_warning directly.
procedure
Analysis: m_current_row_for_warning is reset to 1 during cleanup phase of
stored procedure. When we perform a copy because some statement of procedure
created warning, this reset value is passed to push_warning().
Hence the output is always 1.
Fix: Add a parameter in relevant functions to pass correct value of
row_number and don't use m_current_row_for_warning directly.
Fixup for MDEV-10075
Analysis: ERROR_INDEX implemented in MDEV-10075 was not intuitively clear.
Fix: changed parser to use ROW_NUMBER instead of ERROR_INDEX. Removed
ERROR_INDEX and ERROR_INDEX_SYM from related files. Changed m_error_index
to m_row_number.
use existing Warning_info::m_current_row_for_warning instead
of a newly introduced counter.
But use m_current_row_for_warning to count rows also in the parser
and during prepare.
Extended the parser for GET DIAGNOSTICS to use ERROR_INDEX to get
warning/error index.
Error information is stored in Sql_condition. So it can be used to
store the index of warning/error too. THD::current_insert_index keeps a
track of count for each row that is processed or going to be inserted in the
table (or first row in case of prepare phase). When an error occurs,
first we need to fetch corrected error index (using correct_error_index())
for an error number. This is needed because in prepare phase, the error
may not be because of rows/values. In such case, correct value of
error_index should be 0. Once correct value if fetched, assign it to
Sql_condition::error_index when the object is created during error/warning.
This error_index variable is returned when ERROR_INDEX is used in
GET DIAGNOSTICS.
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)
The ROWNUM() function is for SELECT mapped to JOIN->accepted_rows, which is
incremented for each accepted rows.
For Filesort, update, insert, delete and load data, we map ROWNUM() to
internal variables incremented when the table is changed.
The connection between the row counter and Item_func_rownum is done
in sql_select.cc::fix_items_after_optimize() and
sql_insert.cc::fix_rownum_pointers()
When ROWNUM() is used anywhere in query, the optimization to ignore ORDER
BY in sub queries are disabled. This was done to get the following common
Oracle query to work:
select * from (select * from t1 order by a desc) as t where rownum() <= 2;
MDEV-3926 "Wrong result with GROUP BY ... WITH ROLLUP" contains a discussion
about this topic.
LIMIT optimization is enabled when in a top level WHERE clause comparing
ROWNUM() with a numerical constant using any of the following expressions:
- ROWNUM() < #
- ROWNUM() <= #
- ROWNUM() = 1
ROWNUM() can be also be the right argument to the comparison function.
LIMIT optimization is done in two cases:
- For the current sub query when the ROWNUM comparison is done on the top
level:
SELECT * from t1 WHERE rownum() <= 2 AND t1.a > 0
- For an inner sub query, when the upper level has only a ROWNUM comparison
in the WHERE clause:
SELECT * from (select * from t1) as t WHERE rownum() <= 2
In Oracle mode, one can also use ROWNUM without parentheses.
Other things:
- Fixed bug where the optimizer tries to optimize away sub queries
with RAND_TABLE_BIT set (non-deterministic queries). Now these
sub queries will not be converted to joins. This bug fix was also
needed to get rownum() working inside subqueries.
- In remove_const() remove setting simple_order to FALSE if ROLLUP is
USED. This code was disable a long time ago because of wrong assignment
in the following code. Instead we set simple_order to false if
RAND_TABLE_BIT was used in the SELECT list. This ensures that
we don't delete ORDER BY if the result set is not deterministic, like
in 'SELECT RAND() AS 'r' FROM t1 ORDER BY r';
- Updated parameters for Sort_param::init_for_filesort() to be able
to provide filesort with information where the number of accepted
rows should be stored
- Reordered fields in class Filesort to optimize storage layout
- Added new error messsage to tell that a function can't be used in HAVING
- Added field 'with_rownum' to THD to mark that ROWNUM() is used in the
query.
Co-author: Oleksandr Byelkin <sanja@mariadb.com>
LIMIT optimization for sub query
Adds an implementation for SELECT ... FOR UPDATE SKIP LOCKED /
SELECT ... LOCK IN SHARED MODE SKIP LOCKED
This is implemented only InnoDB at the moment, not in RockDB yet.
This adds a new hander flag HA_CAN_SKIP_LOCKED than
will be used when the storage engine advertises the flag.
When a storage engine indicates this flag it will get
TL_WRITE_SKIP_LOCKED and TL_READ_SKIP_LOCKED transaction types.
The Lex structure has been updated to store both the FOR UPDATE/LOCK IN
SHARE as well as the SKIP LOCKED so the SHOW CREATE VIEW
implementation is simplier.
"SELECT FOR UPDATE ... SKIP LOCKED" combined with CREATE TABLE AS or
INSERT.. SELECT on the result set is not safe for STATEMENT based
replication. MIXED replication will replicate this as row based events."
Thanks to guidance from Facebook commit
193896c466
This helped verify basic test case, and components that need implementing
(even though every part was implemented differently).
Thanks Marko for guidance on simplier InnoDB implementation.
Reviewers: Marko, Monty
MDEV-22199 Add VISIBLE attribute for indexes in CREATE TABLE
This was done to make it easier to read in dumps from MySQL 8.0 generated
with MySQL workbench
* The overlaps check is implemented on a handler level per row command.
It creates a separate cursor (actually, another handler instance) and
caches it inside the original handler, when ha_update_row or
ha_insert_row is issued. Cursor closes on unlocking the handler.
* Containing the same key in index means unique constraint violation
even in usual terms. So we fetch left and right neighbours and check
that they have same key prefix, excluding from the key only the period part.
If it doesnt match, then there's no such neighbour, and the check passes.
Otherwise, we check if this neighbour intersects with the considered key.
* The check does not introduce new error and fails with ER_DUPP_KEY error.
This might break REPLACE workflow and should be fixed separately
Fix:
===
Add "REPLICA" as an alias for "SLAVE". All commands which use "SLAVE" keyword
can be used with new alias "REPLICA".
List of commands:
On Master:
=========
SHOW REPLICA HOSTS <--> SHOW SLAVE HOSTS
Privilege "SLAVE" <--> "REPLICA"
On Slave:
=========
START SLAVE <--> START REPLICA
START ALL SLAVES <--> START ALL REPLICAS
START SLAVE UNTIL <--> START REPLICA UNTIL
STOP SLAVE <--> STOP REPLICA
STOP ALL SLAVES <--> STOP ALL REPLICAS
RESET SLAVE <--> RESET REPLICA
RESET SLAVE ALL <--> RESET REPLICA ALL
SLAVE_POS <--> REPLICA_POS
