The idea of the patch is to separate statement processing logic,
such as parsing, validation of the parsed tree, execution and cleanup,
from global query processing logic, such as logging, resetting
priorities of a thread, resetting stored procedure cache, resetting
thread count of errors and warnings.
This makes PREPARE and EXECUTE behave similarly to the rest of SQL
statements and allows their use in stored procedures.
This patch contains a change in behaviour:
until recently for each SQL prepared statement command, 2 queries
were written to the general log, e.g.
[Query] prepare stmt from @stmt_text;
[Prepare] select * from t1 <-- contents of @stmt_text
The chagne was necessary to prevent [Prepare] commands from being written
to the general log when executing a stored procedure with Dynamic SQL.
We should consider whether the old behavior is preferrable and probably
restore it.
This patch refixes Bug#7115, Bug#10975 (partially), Bug#10605 (various bugs
in Dynamic SQL reported before it was disabled).
- current_arena to stmt_arena: the thread may have more than one
'current' arenas: one for runtime data, and one for the parsed
tree of a statement. Only one of them is active at any moment.
- set_item_arena -> set_query_arena, because Item_arena was renamed to
Query_arena a while ago
- set_n_backup_item_arena -> set_n_backup_active_arena;
the active arena is the arena thd->mem_root and thd->free_list
are currently pointing at.
- restore_backup_item_arena -> restore_active_arena (with the same
rationale)
- change_arena_if_needed -> activate_stmt_arena_if_needed; this
method sets thd->stmt_arena active if it's not done yet.
multi-threaded environment".
To avoid deadlocks between several simultaneously run account management
commands (particularly between FLUSH PRIVILEGES/SET PASSWORD and GRANT
commands) we should always take table and internal locks during their
execution in the same order. In other words we should first open and lock
privilege tables and only then obtain acl_cache::lock/LOCK_grant locks.
sql_parse.cc:
mysqld.cc:
Added --skip-client-character-set-handshake.
When this option is activated, client side character set
(which is sent in handshake) is ignored, and server side
default-character-set value is used for character_set_client
and character_set_results, thus reprodicing 4.0 behaviour.
"Interleaved SPs execution is now binlogged properly, "SELECT spfunc()" is binlogged too.
The known remaining issue is binlogging/replication of "a routine is deleted while it is executed" scenario.
We should not assume that "thd" argument of reload_acl_and_cache() is
non-zero. Failure to do so will cause server to crash when one sends
SIGHUP to it.
- Corrected problem with N-way nested natural joins in PS mode.
- Code cleanup
- More asserts to check consistency of name resolution contexts
- Fixed potential memory leak of name resolution contexts
This allows us to use statement replication with functions and triggers
The following things are fixed with this patch:
- NOW() and automatic timestamps takes the value from the main event for functions and triggers (which allows these to replicate with statement level logging)
- No side effects for triggers or functions with auto-increment values(), last_insert_id(), rand() or found_rows()
- Triggers can't return result sets
Fixes bugs:
#12480: NOW() is not constant in a trigger
#12481: Using NOW() in a stored function breaks statement based replication
#12482: Triggers has side effects with auto_increment values
#11587: trigger causes lost connection error
"Process NATURAL and USING joins according to SQL:2003".
* Some of the main problems fixed by the patch:
- in "select *" queries the * expanded correctly according to
ANSI for arbitrary natural/using joins
- natural/using joins are correctly transformed into JOIN ... ON
for any number/nesting of the joins.
- column references are correctly resolved against natural joins
of any nesting and combined with arbitrary other joins.
* This patch also contains a fix for name resolution of items
inside the ON condition of JOIN ... ON - in this case items must
be resolved only against the JOIN operands. To support such
'local' name resolution, the patch introduces a stack of
name resolution contexts used at parse time.
NOTICE:
- This patch is not complete in the sense that
- there are 2 test cases that still do not pass -
one in join.test, one in select.test. Both are marked
with a comment "TODO: WL#2486".
- it does not include a new test specific for the task
