This task fixes an ineffeciency that is a remainder from MySQL 5.0/5.1. There, subqueries
were optimized in a lazy manner, when executed for the first time. During this lazy optimization
it may happen that the server finds a more efficient subquery engine, and substitute the current
engine of the query being executed with the new engine. This required re-execution of the engine.
MariaDB 5.3 pre-optimizes subqueries in almost all cases, and the engine is chosen in most cases,
except when subquery materialization found that it must use partial matching. In this case, the
current code was performing one extra re-execution although it was not needed at all. The patch
performs the re-execution only if the engine was changed while executing.
In addition the patch performs small cleanup by removing "enum store_key_result" because it is
essentially a boolean, and the code that uses it already maps it to a boolean.
IN ALTER TABLE ... ADD UNIQUE KEY
A bogus debug assertion failure occurred when reporting a duplicate
key on a column prefix of a CHAR column.
This is a regression from Bug#14729221 IN-PLACE ALTER TABLE REPORTS ''
INSTEAD OF REAL DUPLICATE VALUE FOR PREFIX KEYS. The assertion is only
present when UNIV_DEBUG is defined (which it is in debug builds
starting from MySQL 5.5). It is a case of overasserting.
Fix approved by Inaam Rana on IM.
When a DML statement is issued, and if the index merge
access method is chosen, then many rows from the
storage engine will be locked because of the way the
algorithm works. Many rows will be locked, but they
will not be part of the final result set.
To reduce the excessive locking, the locks of unmatched
rows are released by this patch. This patch will
affect only transactions with isolation level
equal to or less stricter than READ COMMITTED. This is
because of the behaviour of ha_innobase::unlock_row().
rb://1296 approved by jorgen and olav.
Problem:-
When we execute a query which has subquery with GROUP BY, ORDER BY and have a
BLOB column,results a memory leak.
Analysis:-
In case of subquery, which have GROUP BY on BLOB and a ORDER BY on other field
and BLOB is not a key. We allocate a tmp buffer to copy_field to take care of
BLOB value.This copy_field value can have copies of its in two join(objects),
so while freeing this copy_field we have to take care that it is
not deleted twice.
The double deletion of tmp_table_param.copy_field is handled by two patches.
One by Kostja :
revid:sp1r-konstantin@mysql.com-20050627101056-55153
Fix the broken test suite in -debug build.
and other by Oleksandr
revid:sp1r-bell@sanja.is.com.ua-20060118114857-19905
Excluded posibility of tmp_table_param.copy_field double deletion (BUG#14851).
both of this patches are commited in different branch and while
merging they both get placed,but there is no need for Kostja patch as Oleksandr
patch handle this.
sql/sql_select.cc:
Bug13726751, tmp_join clean up is not necessary as later in the code we are taking care of cleaning up of tmp_join copy_field.
Problem:-
When we execute a query which has subquery with GROUP BY, ORDER BY and have a
BLOB column,results a memory leak.
Analysis:-
In case of subquery, which have GROUP BY on BLOB and a ORDER BY on other field
and BLOB is not a key. We allocate a tmp buffer to copy_field to take care of
BLOB value.This copy_field value can have copies of its in two join(objects),
so while freeing this copy_field we have to take care that it is
not deleted twice.
The double deletion of tmp_table_param.copy_field is handled by two patches.
One by Kostja :
revid:sp1r-konstantin@mysql.com-20050627101056-55153
Fix the broken test suite in -debug build.
and other by Oleksandr
revid:sp1r-bell@sanja.is.com.ua-20060118114857-19905
Excluded posibility of tmp_table_param.copy_field double deletion (BUG#14851).
both of this patches are commited in different branch and while
merging they both get placed,but there is no need for Kostja patch as Oleksandr
patch handle this.
sql/sql_select.cc:
Bug13726751, tmp_join clean up is not necessary as later in the code we are taking care of cleaning up of tmp_join copy_field.
LEN <= SIZEOF(ULONGLONG)
This bug was caught in the WL#6255 ALTER TABLE...ADD COLUMN in MySQL
5.6, but there is a bug in all InnoDB versions that support
auto-increment columns.
row_search_autoinc_read_column(): When reading the maximum value of
the auto-increment column, and the column only contains NULL values,
return 0. This corresponds to the case when the table is empty in
row_search_max_autoinc().
rb:1415 approved by Sunny Bains
Generalized support for auto-updated and/or auto-initialized timestamp
and datetime columns. This patch is a reimplementation of MySQL's
"WL#5874: CURRENT_TIMESTAMP as DEFAULT for DATETIME columns". In order to
ease future merges, this implementation reused few function and variable
names from MySQL's patch, however the implementation is quite different.
TODO:
The only unresolved problem in this patch is the semantics of LOAD DATA for
TIMESTAMP and DATETIME columns in the cases when there are missing or NULL
columns. I couldn't fully comprehend the logic behind MySQL's behavior and
its relationship with their own documentation, so I left the results to be
more consistent with all other LOAD cases.
The problematic test cases can be seen by running the test file function_defaults,
and observing the test case differences. Those were left on purpose for discussion.
mysqld_safe script did not heed MySQL specific environment variable
$UMASK, leading to divergent behavior between mysqld and mysqld_safe.
Patch adds an approximation of mysqld's behavior to mysqld_safe,
within the bounds dictated by attempt to have mysqld_safe run on
even the most basic of shells (proper '70s sh, not just bash
with a fancy symlink).
Patch also adds approximation of said behavior to mysqld_multi
(in perl).
(backport)
mysqld_safe script did not heed MySQL specific environment variable
$UMASK, leading to divergent behavior between mysqld and mysqld_safe.
Patch adds an approximation of mysqld's behavior to mysqld_safe,
within the bounds dictated by attempt to have mysqld_safe run on
even the most basic of shells (proper '70s sh, not just bash
with a fancy symlink).
Patch also adds approximation of said behavior to mysqld_multi
(in perl).
(backport)
manual merge
mysqld_safe script did not heed MySQL specific environment variable
$UMASK, leading to divergent behavior between mysqld and mysqld_safe.
Patch adds an approximation of mysqld's behavior to mysqld_safe,
within the bounds dictated by attempt to have mysqld_safe run on
even the most basic of shells (proper '70s sh, not just bash
with a fancy symlink).
Patch also adds approximation of said behavior to mysqld_multi
(in perl).
Problem:-
using last_insert_id() on an auto_incremented bigint unsigned does
not work for values which are greater than max-bigint-signed.
Analysis:-
last_insert_id() returns the first auto_incremented value for a column
and an auto_incremented value can have only positive values.
In our code, when we are initializing a last_insert_id object, we are
taking it as a signed BIGINT, So when the auto_incremented value reaches
greater than max signed bigint, last_insert_id gives negative result.
Solution:
When we are fetching the value from last_insert_id, We are setting the
unsigned_flag, so that it take only unsigned BIGINT value.
sql/item_func.cc:
here unsigned value is converted to signed value.
sql/item_func.h:
last_insert_id() gives an auto_incremented value which can be
positive only,so defined it as a unsigned longlong sets the
unsigned_flag to 1.
Problem:-
using last_insert_id() on an auto_incremented bigint unsigned does
not work for values which are greater than max-bigint-signed.
Analysis:-
last_insert_id() returns the first auto_incremented value for a column
and an auto_incremented value can have only positive values.
In our code, when we are initializing a last_insert_id object, we are
taking it as a signed BIGINT, So when the auto_incremented value reaches
greater than max signed bigint, last_insert_id gives negative result.
Solution:
When we are fetching the value from last_insert_id, We are setting the
unsigned_flag, so that it take only unsigned BIGINT value.
sql/item_func.cc:
here unsigned value is converted to signed value.
sql/item_func.h:
last_insert_id() gives an auto_incremented value which can be
positive only,so defined it as a unsigned longlong sets the
unsigned_flag to 1.
REAL DUPLICATE VALUE FOR PREFIX KEYS
innobase_rec_to_mysql(): Invoke dict_index_get_nth_col_or_prefix_pos()
instead of dict_index_get_nth_col_pos() to find the column.
