(Backported to 10.3, addressed review input)
Sj_materialization_picker::check_qep(): fix error in cost/fanout
calculations:
- for each join prefix, add #prefix_rows / TIME_FOR_COMPARE to the cost,
like best_extension_by_limited_search does
- Remove the fanout produced by the subquery tables.
- Also take into account join condition selectivity
optimize_wo_join_buffering() (used by LooseScan and FirstMatch)
- also add #prefix_rows / TIME_FOR_COMPARE to the cost of each prefix.
- Also take into account join condition selectivity
In collaboration with Sergey Vojtovich <svoj@mariadb.org>
The COMPRESSED clause is now a part of the data type and goes immediately
after the data type and length, but before the CHARACTER SET clause,
and before column attributes such as DEFAULT, COLLATE, ON UPDATE,
SYSTEM VERSIONING, engine specific column attributes.
In the old reduction, the COMPRESSED clause was a column attribute.
New syntax:
<varchar or text data type> <length> <compression> <character set> <column attributes>
<varbinary or blob data type> <length> <compression> <column attributes>
New syntax examples:
VARCHAR(1000) COMPRESSED CHARACTER SET latin1 DEFAULT ''
BLOB COMPRESSED DEFAULT ''
Deprecate syntax examples:
VARCHAR(1000) CHARACTER SET latin1 COMPRESSED DEFAULT ''
TEXT CHARACTER SET latin1 DEFAULT '' COMPRESSED
VARBINARY(1000) DEFAULT '' COMPRESSED
As a side effect:
- COMPRESSED is not valid as an SP label name in SQL/PSM routines any more
(but it's still valid as an SP label name in sql_mode=ORACLE)
- COMPRESSED is now allowed in combination with GENERATED ALWAYS AS:
TEXT COMPRESSED GENERATED ALWAYS AS REPEAT('a',1000)
This patch includes:
- MDEV-19639 sql_mode=ORACLE: Wrong SHOW PROCEDURE output for sysvar:=expr
- MDEV-19640 Wrong SHOW PROCEDURE output for SET GLOBAL sysvar1=expr, sysvar2=expr
- Preparatory refactoring for MySQL WL#4179
Detailed change list:
1. Changing sp_create_assignment_lex() to accept the position
in the exact query buffer instead of a "bool no_lookahead".
This actually fixes MDEV-19639.
In the previous reduction sp_create_assignment_lex() was
called too late, when the parser went far the from beginning
of the statement, so only a part of the statement got into
sp_instr_stmt.
2. Generating "SET" or "SET GLOBAL" inside sp_create_assignment_instr()
depending on the option type.
This fixes MDEV-19640.
In the previous reduction the code passed (through no_lookahead)
the position of the
word GLOBAL inside sp_create_assignment_lex(), which
worked only for the left-most assignment.
3. Fixing the affected rules to use:
- ident_cli instead of ident
- ident_cli_set_usual_case instead of ident_set_usual_case
4. Changing the input parameter in:
- LEX::set_system_variable()
- LEX::call_statement_start()
- LEX::set_variable()
from just LEX_CSTRING to Lex_ident_sys_st for stricter data type constrol:
to make sure that noone passes an ident_cli
(a fragment of the original query in the client character set)
instead of server-side identifier
(utf8 identifier allocated on THD when needed).
5. Adding Lex_ident_sys() in places where the affected functions are called.
6. Moving all calls of sp_create_assignment_lex() to the places
just before parsing set_expr_or_default.
This makes the grammar clearer, because
sp_create_assignment_lex() and sp_create_assignment_instr()
now stay near each other, so the balance of LEX's push/pop
can be read easier.
This will also help to WL#4179.
7. Adding class sp_lex_set_var
Moving the initialization code from
sp_create_assignment_lex() to the constructor of sp_lex_set_var.
This will also help to WL#4179.
8. Moving a part of the "set" grammar rule into a separate
rule "set_param".
This makes the grammar easier to read and removes
one shift/reduce conflict.
query with VALUES()
A table value constructor can be used in all contexts where a select
can be used. In particular an ORDER BY clause or a LIMIT clause or both
of them can be attached to a table value constructor to produce a new
query. Unfortunately execution of such queries was not supported.
This patch fixes the problem.
This patch was originally made by Anel Husakovic.
Skip `PACKAGE` and `PACKAGE BODY` records quickly.
These stored objects do not have any parameters or return values
(only procedures and functions have).
So no needs to build a `CREATE` statement
(in `Sp_handler::sp_load_for_information_schema()`) and parse it:
this won't give us any data useful for `INFORMATION_SCHEMA.PARAMETERS`.
Part#2 (final): rewritting the code to pass the correct enum_sp_aggregate_type
to the sp_head constructor, so sp_head never changes its aggregation type
later on. The grammar has been simplified and defragmented.
This allowed to check aggregate specific instructions right after
a routine body has been scanned, by calling new LEX methods:
sp_body_finalize_{procedure|function|trigger|event}()
Moving some C++ code from *.yy to a few new helper methods in LEX.
Part of MDEV-5336 Implement LOCK FOR BACKUP
- Added new locks to MDL_BACKUP for all stages of backup locks and
a new MDL lock needed for backup stages.
- Renamed MDL_BACKUP_STMT to MDL_BACKUP_DDL
- flush_tables() takes a new parameter that decides what should be flushed.
- InnoDB, Aria (transactional tables with checksums), Blackhole, Federated
and Federatedx tables are marked to be safe for online backup. We are
using MDL_BACKUP_TRANS_DML instead of MDL_BACKUP_DML locks for these
which allows any DML's to proceed for these tables during the whole
backup process until BACKUP STAGE COMMIT which will block the final
commit.
sp_instr_cursor_copy_struct::exec_core() created TYPELIBs on a wrong mem_root,
the one which is initialized in sp_head::execute(), this code:
/* init per-instruction memroot */
init_sql_alloc(&execute_mem_root, "per_instruction_memroot",
MEM_ROOT_BLOCK_SIZE, 0, MYF(0));
This memory root cleans up after every sp_instr_xxx executed, so later
sp_instr_cfetch::execute() tried to use already freed and trashed memory.
Changing sp_instr_cursor_copy_struct::exec_core() to call tmp.export_structure()
inside this block (not outside of it):
thd->set_n_backup_active_arena(thd->spcont->callers_arena, ¤t_arena);
...
thd->restore_active_arena(thd->spcont->callers_arena, ¤t_arena);
So now TYPELIBs created by sp_instr_cursor_copy_struct::exec_core() are
still available and valid when sp_instr_cfetch::execute() is called.
They are freed at the end of dispatch_command() corresponding to
the "CALL p1" statement.
MDEV-17660 sql_mode=ORACLE: Some keywords do not work as label names: history, system, versioning, without
MDEV-17661 Add sql_mode specific tokens for the keyword DECODE
Changing the way how a cursor is opened to fetch its structure only,
e.g. for a cursor FOR loop record variable.
The old methods with setting thd->lex->limit_rows_examined to an Item_uint(0)
was not reliable and could push these messages into diagnostics area:
The query examined at least 1 rows, which exceeds LIMIT ROWS EXAMINED (0)
The new method should be more reliable, as it completely prevents the call
of do_select() in JOIN::exec_inner() during the cursor structure discovery,
so the execution of the cursor SELECT query returns immediately after the
preparation step (when the result row structure becomes known),
without even entering the code that fetches the result rows.