forever, cannot be killed
mysql_rm_table_no_locks() does TDC_RT_REMOVE_ALL which waits while
share is closed. The table normally is open only as OPEN_STUB, this is
what parser does for CREATE TABLE. But for SELECT the table is opened
not as a stub. If it is the same table name we anyway have two
TABLE_LIST objects: stub and not stub. So for "not stub"
TDC_RT_REMOVE_ALL sees open count and decides to wait until it is
closed. And it hangs because that was opened in the same thread.
The fix disables subqueries in CHECK expression at parser
level. Thanks to Sergei Golubchik <serg@mariadb.org> for the patch.
It was not possible to use a package body variable as a
fetch target:
CREATE PACKAGE BODY pkg AS
vc INT := 0;
FUNCTION f1 RETURN INT AS
CURSOR cur IS SELECT 1 AS c FROM DUAL;
BEGIN
OPEN cur;
FETCH cur INTO vc; -- this returned "Undeclared variable: vc" error.
CLOSE cur;
RETURN vc;
END;
END;
FETCH assumed that all fetch targets reside of the same sp_rcontext
instance with the cursor. This patch fixes the problem.
Now a cursor and its fetch target can reside in different sp_rcontext
instances.
Details:
- Adding a helper class sp_rcontext_addr
(a combination of Sp_rcontext_handler pointer and an offset in the rcontext)
- Adding a new class sp_fetch_target deriving from sp_rcontext_addr.
Fetch targets in "FETCH cur INTO target1, target2 ..." are now collected
into this structure instead of sp_variable.
sp_variable cannot be used any more to store fetch targets,
because it does not have a pointer to Sp_rcontext_handler
(it only has the current rcontext offset).
- Removing members sp_instr_set members m_rcontext_handler and m_offset.
Deriving sp_instr_set from sp_rcontext_addr instead.
- Renaming sp_instr_cfetch member "List<sp_variable> m_varlist"
to "List<sp_fetch_target> m_fetch_target_list".
- Fixing LEX::sp_add_cfetch() to return the pointer to the
created sp_fetch_target instance (instead of returning bool).
This helps to make the grammar in sql_yacc.c simpler
- Renaming LEX::sp_add_cfetch() to LEX::sp_add_instr_cfetch(),
as `if(sp_add_cfetch())` changed its meaning to the opposite,
to avoid automatic wrong merge from earlier versions.
- Chaning the "List<sp_variable> *vars" parameter to sp_cursor::fetch
to have the data type "List<sp_fetch_target> *".
- Changing the data type of "List<sp_variable> &vars" in
sp_cursor::Select_fetch_into_spvars::send_data_to_variable_list()
to "List<sp_fetch_target> &".
- Adding THD helper methods get_rcontext() and get_variable().
- Moving the code from sql_yacc.yy into a new LEX method
LEX::make_fetch_target().
- Simplifying the grammar in sql_yacc.yy using the new LEX method.
Changing the data type of the bison rule sp_fetch_list from "void"
to "List<sp_fetch_target> *".
The segfault in wsrep_check_sequence is due to a
null pointer deference on:
db_type= thd->lex->create_info.db_type->db_type;
Where create_info.db_type is null. This occured under
a used_engine==true condition which is set in the calling
function based on create_info.used_fields==HA_CREATE_USED_ENGINE.
However the create_info.used_fields was a left over
from the parsing of the previous failed CREATE TABLE where
because of its failure, db_type wasn't populated.
This is corrected by cleaning the create_info when we start
to parse ALTER SEQUENCE statements.
Other paths to wsrep_check_sequence is via CREATE SEQUENCE
and CREATE TABLE LIKE which both initialize the create_info
correctly.
MariaDB in a COLLATE clause supported 'binary' only as an identifier:
COLLATE `binary`
Fixing the parser to understand 'binary' as a keyword:
COLLATE binary
This is for MySQL compatibility.
Search conditions were evaluated using val_int(), which was wrong.
Fixing the code to use val_bool() instead.
Details:
- Adding a new item_base_t::IS_COND flag which marks Items used
as <search condition> in WHERE, HAVING, JOIN ON, CASE WHEN clauses.
The flag is at the parse time.
These expressions must be evaluated using val_bool() rather than val_int().
Note, the optimizer creates more Items which are used as search conditions.
Most of these items are not marked with IS_COND yet. This is OK for now,
but eventually these Items can also be fixed to have the flag.
- Adding a method Item::is_cond() which tests if the Item has the IS_COND flag.
- Implementing Item_cache_bool. It evaluates the cached expression using
val_bool() rather than val_int().
Overriding Type_handler_bool::Item_get_cache() to create Item_cache_bool.
- Implementing Item::save_bool_in_field(). It uses val_bool() rather than
val_int() to evaluate the expression.
- Implementing Type_handler_bool::Item_save_in_field()
using Item::save_bool_in_field().
- Fixing all Item_bool_func descendants to implement a virtual val_bool()
rather than a virtual val_int().
- To find places where val_int() should be fixed to val_bool(), a few
DBUG_ASSERT(!is_cond()) where added into val_int() implementations
of selected (most frequent) classes:
Item_field
Item_str_func
Item_datefunc
Item_timefunc
Item_datetimefunc
Item_cache_bool
Item_bool_func
Item_func_hybrid_field_type
Item_basic_constant descendants
- Fixing all places where DBUG_ASSERT() happened during an "mtr" run
to use val_bool() instead of val_int().
(Polished initial patch by Alexey Botchkov)
Make the code handle DEFAULT values of any datatype
- Make Json_table_column::On_response::m_default be Item*, not LEX_STRING.
- Change the parser to use string literal non-terminals for producing
the DEFAULT value
-- Also, stop updating json_table->m_text_literal_cs for the DEFAULT
value literals as it is not used.
Improve performance of queries like
SELECT * FROM t1 WHERE field = NAME_CONST('a', 4);
by, in this example, replacing the WHERE clause with field = 4
in the case of ref access.
The rewrite is done during fix_fields and we disambiguate this
case from other cases of NAME_CONST by inspecting where we are
in parsing. We rely on THD::where to accomplish this. To
improve performance there, we change the type of THD::where to
be an enumeration, so we can avoid string comparisons during
Item_name_const::fix_fields. Consequently, this patch also
changes all usages of THD::where to conform likewise.
The @@global.character_set_client variable could erroneously be set
to a non-default collation of its character set, which further made
the `SET NAMES DEFAULT` statement crash the server.
Fixing the code to make sure that the global value these variables:
@@character_set_client
@@character_set_connection
@@character_set_server
@@character_set_database
@@character_set_connection
point to the default compiled collations of the character set.
I checked all stack overflow potential problems found with
gcc -Wstack-usage=16384
and
clang -Wframe-larger-than=16384 -no-inline
Fixes:
Added '#pragma clang diagnostic ignored "-Wframe-larger-than="'
to a lot of function to where stack usage large but resonable.
- Added stack check warnings to BUILD scrips when using clang and debug.
Function changed to use malloc instead allocating things on stack:
- read_bootstrap_query() now allocates line_buffer (20000 bytes) with
malloc() instead of using stack. This has a small performance impact
but this is not releant for bootstrap.
- mroonga grn_select() used 65856 bytes on stack. Changed it to use
malloc().
- Wsrep_schema::replay_transaction() and
Wsrep_schema::recover_sr_transactions().
- Connect zipOpen3()
Not fixed:
- mroonga/vendor/groonga/lib/expr.c grn_proc_call() uses
43712 byte on stack. However this is not easy to fix as the stack
used is caused by a lot of code generated by defines.
- Most changes in mroonga/groonga where only adding of pragmas to disable
stack warnings.
- rocksdb/options/options_helper.cc uses 20288 of stack space.
(no reason to fix except to get rid of the compiler warning)
- Causes using alloca() where the allocation size is resonable.
- An issue in libmariadb (reported to connectors).
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.
