of bugs easier (MDEV-8919, MDEV-10304, MDEV-10305, MDEV-10307)
- Adding Item::push_note_converted_to_negative_complement() and
Item::push_note_converted_to_positive_complement()
- Adding virtual methods Item::val_int_signed_typecast() and
Item::val_int_unsigned_typecast()
- Moving COLUMN_GET() related code from
Item_func_signed::val_int() and Item_func_unsigned::val_int() to
Item_dyncol_get::val_int_signed_typecast() and
Item_dyncol_get::val_int_unsigned_typecast()
- Moving Item_func_signed::val_int_from_str() to Item::val_int_from_str()
and changing it to get the value from "this" instead of args[0].
The patch does not change behaviour. It's only to simplify fixing of the
mentioned bugs. It will also simplify switching the CAST related code to
use the type handler infrastructure easier (soon).
Decimals with float, double and decimal now works the following way:
- DECIMAL_NOT_SPECIFIED is used when declaring DECIMALS without a firm number
of decimals. It's only used in asserts and my_decimal_int_part.
- FLOATING_POINT_DECIMALS (31) is used to mark that a FLOAT or DOUBLE
was defined without decimals. This is regarded as a floating point value.
- Max decimals allowed for FLOAT and DOUBLE is FLOATING_POINT_DECIMALS-1
- Clients assumes that float and double with decimals >= NOT_FIXED_DEC are
floating point values (no decimals)
- In the .frm decimals=FLOATING_POINT_DECIMALS are used to define
floating point for float and double (31, like before)
To ensure compatibility with old clients we do:
- When storing float and double, we change NOT_FIXED_DEC to
FLOATING_POINT_DECIMALS.
- When creating fields from .frm we change for float and double
FLOATING_POINT_DEC to NOT_FIXED_DEC
- When sending definition for a float/decimal field without decimals
to the client as part of a result set we convert NOT_FIXED_DEC to
FLOATING_POINT_DECIMALS.
- variance() and std() has changed to limit the decimals to
FLOATING_POINT_DECIMALS -1 to not get the double converted floating point.
(This was to preserve compatiblity)
- FLOAT and DOUBLE still have 30 as max number of decimals.
Bugs fixed:
variance() printed more decimals than we support for double values.
New behaviour:
- Strings now have 38 decimals instead of 30 when converted to decimal
- CREATE ... SELECT with a decimal with > 30 decimals will create a column
with a smaller range than before as we are trying to preserve the number of
decimals.
Other changes
- We are now using the obsolete bit FIELDFLAG_LEFT_FULLSCREEN to specify
decimals > 31
- NOT_FIXED_DEC is now declared in one place
- For clients, NOT_FIXED_DEC is always 31 (to ensure compatibility).
On the server NOT_FIXED_DEC is DECIMAL_NOT_SPECIFIED (39)
- AUTO_SEC_PART_DIGITS is taken from DECIMAL_NOT_SPECIFIED
- DOUBLE conversion functions are now using DECIMAL_NOT_SPECIFIED instead of
NOT_FIXED_DEC
Remove the assert. We cannot verify that
global_memory_used value is valid (>=0)
because some of updates are cached in individual THD's
(e.g. THD1 can have +300 cached, while the other THD2
can have -300 cached. If the second THD exists before
the first one, global_memory_used will be -300
temporarily).
Instead add the assert just before the exit, when all
THDs been already destroyed.
Since a query can now refer to the same temporary table
multiple times, find_dup_table()/find_table_in_list()
have been updated to also consider this new possibility.
Temporary table being created by outer statement
should not be visible to inner statement. And if
inner statement creates a table with same name.
The whole statement should fail with
ER_TABLE_EXISTS_ERROR.
Implemented by temporarily de-linking the TABLE_SHARE
being created by outer statement so that it remains
hidden to the inner statement.
mysqld maintains a list of TABLE objects for all temporary
tables created within a session in THD. Here each table is
represented by a TABLE object.
A query referencing a particular temporary table for more
than once, however, failed with ER_CANT_REOPEN_TABLE error
because a TABLE_SHARE was allocate together with the TABLE,
so temporary tables always had only one TABLE per TABLE_SHARE.
This patch lift this restriction by separating TABLE and
TABLE_SHARE objects and storing TABLE_SHAREs for temporary
tables in a list in THD, and TABLEs in a list within their
respective TABLE_SHAREs.
- unused TABLE_SHARE::deleting and TABLE_LIST::deleting flags were removed
- kill_delayed_threads_for_table() and intern_close_table() are now private
methods of table cache
- removed free_share flag of closefrm(): it was never used for temporary
tables and was rarely useful for regular tables
because thread_count means just that: number of THDs
and shutdown code looks at it to know when to free
shared data structures that THD uses.
This fixes random crashes in ~THD on shutdown
according to the standard, the gtrid/bqual pair must be
"globally unique", so XIDs are equal if their gtrids and
bquals are identical, formatID simply tells how
gtrid/bqual were generated. But if formatID == -1
(it means "null") gtrid/bqual don't have any value at all.
This fixes main.xa_sync failure in
./mtr main.quary_cache_debug main.xa_sync
- To ensure that mallocs are marked for the correct THD, even if it's
allocated in another thread, I added the thread_id to the THD constructor
- Added st_my_thread_var to thr_lock_info_init() to avoid a call to my_thread_var
- Moved things from THD::THD() to THD::init()
- Moved some things to THD::cleanup()
- Added THD::free_connection() and THD::reset_for_reuse()
- Added THD to CONNECT::create_thd()
- Added THD::thread_dbug_id and st_my_thread_var->dbug_id. These are needed
to ensure that we have a constant thread_id used for debugging with a THD,
even if it changes thread_id (=connection_id)
- Set variables.pseudo_thread_id in constructor. Removed not needed sets.
As a side effect tc_remove_all_unused_tables() has to call
tc_wait_for_mdl_deadlock_detector() once per TABLE object now, while it called
it only once before. This should be acceptable since actual wait will still be
performed only once. It only adds redundant checks for all_tables_refs.
This is mostly needed to hide all references to free_tables, so that further
implementation of multi-instance list can be done completely inside
table_cache.cc
Allowing GROUP_CONCAT(... ORDER BY ..) in queries with ROLLUP.
The story of the related code:
1. The original patch from Wax
commit: 0b505fb437
date: Tue Mar 18 03:07:40 2003
opt_gorder_clause reused the regular order_clause,
which already had some protection against ROLLUP queries:
order_clause:
ORDER_SYM BY
{
LEX *lex=Lex;
if (lex->current_select->linkage != GLOBAL_OPTIONS_TYPE &&
lex->current_select->select_lex()->olap !=
UNSPECIFIED_OLAP_TYPE)
{
net_printf(lex->thd, ER_WRONG_USAGE,
"CUBE/ROLLUP",
"ORDER BY");
YYABORT;
}
} order_list;
The assumption that ORDER BY in group_concat() had to have
the same ROLLUP restriction (with order_clause) was wrong.
Moreover, GROUP_CONCAT() in select_item_list was not affected
by this restriction, because WITH ROLLUP goes after
select_item_list and therefore sel->olap is always equal
to UNSPECIFIED_OLAP_TYPE during select_item_list.
GROUP BY was not affected for two reasons:
- it goes before WITH ROLLUP and sel->olap is still
UNSPECIFIED_OLAP_TYPE
- Aggregate functions like AVG(), GROUP_CONCAT() in GROUP BY
are not allowed
So only GROUP_CONCAT() in HAVING and ORDER BY clauses
were erroneously affected by this restriction.
2. Bug#27848 rollup in union part causes error with order of union
commit: 3f6073ae63
Author: unknown <igor@olga.mysql.com> 2007-12-15 01:42:46
The condition in the ROLLUP protection code became more complex.
Note, opt_gconcat_order still reused the regular order_clause.
3. Bug#16347426 ASSERTION FAILED: (SELECT_INSERT &&
!TABLES->NEXT_NAME_RESOLUTION_TABLE) || !TAB
commit: 2d83663380
author: Chaithra Gopalareddy <chaithra.gopalareddy@oracle.com>
date: 2013-04-14 06:00:49
opt_gorder_clause was refactored not to use order_clause and
to collect information directly to select->gorder_list.
The ROLLUP protection code was duplicated from order_clause
to the new version of opt_gorder_clause.
- Validate the specified wsrep_start_position value by also
checking the return status of wsrep->sst_received. This also
ensures that changes in wsrep_start_position is not allowed
when the node is not in JOINING state.
- Do not allow decrease in seqno within same UUID.
- The initial checkpoint in SEs should be [0...:-1].
Using /*empty*/, union_list, union_order_or_limit instead.
This is to get rid of lex->current_select->braces easier
(separately in union_list and in union_order_or_limit)
- Moving opt_union_order_or_limit inside union_opt,
as it's not used in other places any more.
- Changing union_opt to have no type.
Earlier (before all MDEV-8909 dependency tasks) it had the <num> type,
and it's return value was used to generate errors.
Now union_opt does not need a return value because the grammar
disallows ORDER and LIMIT clauses in wrong context.
(to simplify further MDEV-8909 changes)
1. Better semantic readability:
- Moving get_select_lex_derived inside select_derived_init
and decomposing it into get_select_lex and
$1->init_nested_join(lex->thd)
- Moving DBUG_ASSERT($1 == Lex->current_select) inside
select_derived_init
Now init_nested_join() and end_nested_join() reside inside
the same rule select_derived_init.
(It's very likely that they can be further removed,
as there are no any joins in this rule).
3. Better grammar readability:
Moving SELECT_SYM from select_derived_init to derived_query_specification.
It's easier to read a rule when it starts from a terminal symbol.
1. Moving the "| get_select_lex_derived select_derived_init" part of
select_derived into a separate new rule derived_query_specification.
2. Using derived_query_specification directly in select_derived_union
rather than in select_derived.
3. Moving the sequence "opt_order_clause opt_limit_clause opt_select_lock_type"
from select_derived2 to select_derived_union,
after derived_query_specification.
Effectively, the parser now does not go through the sequence
"opt_order_clause opt_limit_clause ... opt_union_order_or_limit" any more.
This fixes the problem with double LIMIT clause and removes 2 shift/reduce
conflicts.
"MDEV-8909 union parser cleanup" changes.
When the server parses a query like
SELECT * FROM (SELECT 1);
a sequence of calls
st_select_lex::init_nested_join() ..
st_select_lex::end_nested_join()
was performed two times (tested in gdb).
Both pairs of calls seem to be redundant for a query
like this, because there are actually no any joins here.
This patch moved "table_ref_select" inside "select_derived",
which revealed that one the pairs was definitely redundant:
After this transformation we got an init_nested_join()
immediately followed by end_nested_join() for the same st_select_lex,
which has no any sense. So this pair of calls was removed.
