Add SQL_CACHE=0|1 option for tables to disable/enable query caches if
table is part of the query.
SQL_CACHE option can be disable for a table by using SQL_CACHE=DEFAULT
Also provide a workaround for the problem described at:
MDEV-6631 "No cache directive(SQL_CACHE) query still wait for
query cache lock" on query_cache_type=DEMAND mode"
by adding DEMAND_STRICT mode.
The new mode is needed as modifying how DEMAND works would made the
change backward incompatible.
query_cache_type has now following options (0-2 are same as before)
OFF (0) = Query cache off
ON (1) = Query cache on, all queries are cached except queries marked
with SQL_NO_CACHE
DEMAND (2) = Query cache on, only queries marked with SQL_CACHE are cached
DEMAND_STRICT
(3) = Query cache on, only queries starting with SELECT SQL_CACHE
are cached. This avoids a query cache lock+lookup for every
query.
TABLES (4) = Query cache on, only cache queries marked with SQL_CACHE or
where all used tables are using the create option SQL_CACHE=1
Note that if any of the tables used in the query has the create option
SQL_CACHE=0 or is a system table, temporary table or other non
cacheable table, then the query will not be cached.
SHOW CREATE TABLE prints SQL_CACHE=0|1 when the option is set. For tables
where the option can never apply (temporary tables, tables in the mysql
database, and engines that do not support the query cache) it is printed
as /* SQL_CACHE=1 */.
co-author: Seunguck Lee
- Took some changes related to MDEV-6631 from his patch.
* keep `vec_len >= subdist_part * 2` logic in one place only
* keep "distance-greater-than" mode logic in one place only
* simplify VECTOR_DIMENSIONS (no need to have a special ctx->vec_len
path if the other one always works)
* new plugin = maturity beta
* remove redundant casts, etc
* moved vector_indexes_fields_enum to the global scope to use it
for setting schema->idx_field1/schema->idx_field2
* open the hlindex graph table, if needed, otherwise most values
are unknown unless a user did vector search before
* added TABLE_CATALOG column
* remove CACHE_OVERFLOWS column, doesn't work as implemented,
the fix is complex and isn't worth it
* add privilege checks (MDEV-40793)
in the test:
* prefer query_vertical for readability
* select all columns at least once
* select INDEX_SIZE even if engine-dependent, use rdiff files
* test how get_all_tables only open one specific table, and
even only .frm file, if possible
Make show_create_table_ex/get_default_field_value() use
Field::real_maybe_null(), not maybe_null().
Before, the difference didn't matter as show_create_table_ex() was
only invoked in SHOW CREATE TABLE where columns are not made NULLable.
Optimizer context code invokes show_create_tableas show_create_table_ex()
in all queries, so now the distinction matters.
This task loads the stats of the tables that are used in a query,
from the trace into the optimizer. This feature is controlled
by optimizer_replay_context, and points to an user defined variable name,
that has the context information.
The stats such as num_of_records present in the table, indexes if present,
their names, along with the average number of records_per_key
with in each index, cost of reading an index are loaded from the trace.
Additionally, stats from range analysis i.e. ranges, and the
corresponding number of records, along with their costs are also
loaded from the trace.
The trace context which is in JSON format is firstly set into the
user defined session variable, and this variable name is set to
optimizer_replay_context system variable.
Later, when a user issues a query, the contents of the json context is
parsed and an in memory representation is built using the class
Optimizer_context_replay. This class is then used by the optimizer
to update and save original values of the tables, indexes, and range stats
in the methods "set_statistics_for_table()" of sql_statistics.cc, and
"check_quick_select()" of opt_range.cc.
After the query gets finished, the statistics that were updated
in the optimizer are restored back to the saved original values.
The entry point for parsing the json structure is in
"mysql_execute_command()" of sql_parse.cc, and similarly exit point
i.e. to restore the saved stats of the optimizer is at the end
of the same method.
Two new warning/error messages are introduced:
ER_JSON_OPTIMIZER_REPLAY_CONTEXT_PARSE_FAILED, and
ER_JSON_OPTIMIZER_REPLAY_CONTEXT_MATCH_FAILED
CREATE SERVER used to:
* support arbitrary options in backticks and not in backticks
* hard-coded historical options worked *only* without backticks
* PORT range was different when given as a number or a string
all that is fixed, unused keywords are removed
The "is it my own thread" check compared the login user name
(Security_context::user) and ignored the host, so u1@localhost could see
and kill threads of u1@'127.0.0.1'.
Compare the authenticated account instead:
* all comparisons are done in sctx->is_priv_user() now
* change user_matches() to priv_user_matches(), which uses is_priv_user()
* use it in KILL, KILL USER, SHOW PROCESSLIST, I_S.PROCESSLIST,
COM_PROCESS_INFO and SHOW EXPLAIN/ANALYZE FOR.
* all the remaining places use is_priv_user() directly instead
of doing strcmp: SHOW GRANTS, SHOW CREATE PROCEDURE, I_S.VIEWS,
the DEFINER clause, optimizer trace and change_security_context().
Assisted-by: Claude:claude-5-opus
Store all READ_ONLY sysvar values in the read_only_root
Even though READ_ONLY sysvars are protected, for string variables
it usually means that the pointer cannot be changed. The value it
points to - the string itself - still can be. Let's store all
values of string READ_ONLY sysvars in the read_only_root.
sysvars that point directly into argv are copied to read_only_root.
sysvars that have their values calculated and allocated now
must be explicitly marked with PREALLOCATED to let it know they
have to be free()-d.
Assisted-By: Claude:claude-4.8-opus
Protect all READ_ONLY sysvars from run-time changes.
Put them into a separate section and use my_virtual_mem_protect()
to make this section read-only before the server starts accepting
connections.
Verify that they're all protected in the sys_var constructor.
One exception: opt_noacl (--skip-grant-tables) can be changed
from 1 to 0 on FLUSH PRIVILEGES. Let's briefly drop the
protection for this 1->0 change. It can be needed only once
in a server lifetime and only if it was started with --skip-grant-tables
On shutdown the protection is removed, making variables writable
again because shutdown resets some of them during the cleanup
Assisted-By: Claude:claude-4.8-opus
WITH GRANT OPTION is not a privilege in the standard sense,
so whenever INFORMATION_SCHEMA visibility dictates "any privilege"
this does not include WITH GRANT OPTION, even though GRANT_ACL
is a privilege in MariaDB.
Assisted-By: Claude:claude-4.6-sonnet
1.
Only allow #mysql50# prefix on table names that
can not be decoded from a file name to a table name.
It is an error to put this prefix on a name that can be accessed
as a valid table name without a prefix. Use `t1` not `#mysql50#t1`,
use `a-b` not `#mysql50#a@002db`.
2.
Don't allow creation of new tables with the #mysql50# prefix.
Except when in SQLCOM_ALTER_DB_UPGRADE - main.upgrade test runs
ALTER DATABASE `#mysql50#mysqltest-1` UPGRADE DATA DIRECTORY NAME;
This command moves tables from the old db name to the new db name,
and some of these tables also have old #mysql50# names.
3.
Also don't allow to create such databases, views, partitions,
subpartitions, sequences, triggers.
Three problems:
1. Option value specified as `foo bar` was not quoted,
printed as foo bar, breaking CREATE TABLE.
2. Option value that included */ was printed as is, in unknown
options when the whole option was commented out, this broke the
comment: /* opt='val*/ue' */
3. Option names can include */ too, `opt*/ion`=1
Fix: simplify value printing, ignore the original quoting, always
print the value quoted as a string. Break comment markers with an
escape (as *\/) if inside a comment. As \-escapes don't work inside,
backticks, we cannot use `-quoting for option values at all.
For the same reason we cannot allow */ inside option names, thus
let's only allow keywords for option names and reject fancy names
even if IGNORE_BAD_TABLE_OPTIONS is in force.
gcc 15.1.15 gives the following error, possible from static struct
initialization:
/my/maria-11.8/sql/sql_show.cc: In function ‘void __static_initialization_and_destruction_0()’:
/my/maria-11.8/sql/sql_show.cc:11356:1: error: the frame size of 62880 bytes is larger than 16384 bytes [-Werror=frame-larger-than=]
Fixed by adding PRAGMA_DISABLE_CHECK_STACK_FRAME to sql_show.cc
This patch implements support for implicit query block (QB) names in
optimizer hints, allowing hints to reference query blocks and tables
within derived tables, views and CTEs without requiring explicit
QB_NAME hints.
Examples.
-- Addressing a table inside a derived table using implicit QB name
select /*+ no_index(t1@dt) */ *
from (select * from t1 where a > 10) as DT;
-- this is an equivalent to:
select /*+ no_index(t1@dt) */ * from
(select /*+ qb_name(dt)*/ * from t1 where a > 10) as DT;
-- Addressing a query block corresponding to the derived table
select /*+ no_bnl(@dt) */ *
from (select * from t1, t2 where t.1.a > t2.a) as DT;
-- View
create view v1 as select * from t1 where a > 10 and b > 100;
-- referencing a table inside a view by implicit QB name:
select /*+ index_merge(t1@v1 idx_a, idx_b) */ *
from v1, t2 where v1.a = t2.a;
-- equivalent to:
create view v1 as select /*+ qb_name(qb_v1) */ *
from t1 where a > 10 and b > 100;
select /*+ index_merge(t1@qb_v1 idx_a, idx_b) */ *
from v1, t2 where v1.a = t2.a;
-- CTE
with aless100 as (select a from t1 where b <100)
select /*+ index(t1@aless100) */ * from aless100;
-- equivalent to:
with aless100 as (select /*+ qb_name(aless100) */ a from t1 where b <100)
select /*+ index(t1@aless100) */ * from aless100;
Limitations:
- Only SELECT statements support implicit QB names. DML operations
(UPDATE, DELETE, INSERT) only support explicit QB names
Vector indexes are stored in a separate internal table (hlindex).
The main table's storage engine knows nothing about it, INDEX_LENGTH
was always reported as 0 for tables with vector indexes.
the fix: after calling info() on the main table handler in sql_show.cc,
check if the table has an hlindex, open it if needed, and add its data_file_length to
index_file_length before writing to the information schema record.
Problem:
UBSAN reports runtime errors in string comparision functions when
pointer arithmetic is done without checking NULL.
Fix:
- Add debug asserts in `strnncoll` function to catch NULL pointers.
- Define a new function `streq_safe` as a replacement for `streq`,
capable of handling NULL pointers. Replace `streq` with `streq_safe`
at multiple call sites, identified by the debug asserts.
- Add empty identifier checks in `is_infoschema_db` and
`is_perfschema_db` before calling the deep character-set based
comparision.
- Add IS_DEPRECATED and DEPRECATION_REPLACEMENT columns to the
SYSTEM_VARIABLES information schema table
- Add a mysql-test case to verify the new columns output correctly
gcc 15.1.15 gives the following error, possible from static struct
initialization:
/my/maria-11.8/sql/sql_show.cc: In function ‘void __static_initialization_and_destruction_0()’:
/my/maria-11.8/sql/sql_show.cc:11356:1: error: the frame size of 62880 bytes is larger than 16384 bytes [-Werror=frame-larger-than=]
Fixed by adding PRAGMA_DISABLE_CHECK_STACK_FRAME to sql_show.cc
paritioning has its own method for printing engine options,
it wasn't consistent with how table options were printed - didn't
use quotes, ignored sql_mode, so wasn't future and dump/import safe.
let's get rid of it and use the same method that prints per-table
engine options.
let's simplify the code by removing copying of part_elem->connect_string
to table->s->connect_string. Move CONNECTION support from he server into
engines, engines define TOPTION("CONNECTION") if they want to support it,
it's stored in the option_struct and handled by the option_struct fix.
Problems:
* Mroonga used CONNECTION for something but there were no tests for it.
Removed Mroonga support for CONNECTION as requested by the maintainer
in MDEV-38530
* DROP/ALTER SERVER command used to close all tables using the server
in question, avoiding the need for FLUSH TABLES. This functionality
never worked for partitioned tables anyway and is now removed. Will be
done properly in MDEV-37827.
some I_S tables require "any non-SELECT privilege on the table".
If only SELECT was granted on the global level and something non-SELECT
on the schema level, then we need to check schema level privileges
explicitly, because check_grant() doesn't do that and get_all_tables()
doesn't look deeper if SELECT is present on the global level.
