memory
The server was doing a bad class typecast causing setting of
wrong value for the maximum number of items in an internal
structure used in equality propagation.
Fixed by not doing the wrong typecast and asserting the type
of the Item where it should be done.
values
We should re-set the access method functions when changing the access
method when switching to another index to avoid sorting.
Fixed by doing a little re-engineering : encapsulating all the function
assignment into a special function and calling it when flipping the
indexes.
memory
The server was doing a bad class typecast causing setting of
wrong value for the maximum number of items in an internal
structure used in equality propagation.
Fixed by not doing the wrong typecast and asserting the type
of the Item where it should be done.
values
We should re-set the access method functions when changing the access
method when switching to another index to avoid sorting.
Fixed by doing a little re-engineering : encapsulating all the function
assignment into a special function and calling it when flipping the
indexes.
only const tables
The problem was caused by two shortcuts in the optimizer that
are inapplicable in the ROLLUP case.
Normally in a case when only const tables are involved in a
query, DISTINCT clause can be safely optimized away since there
may be only one row produced by the join. Similarly, we don't
need to create a temporary table to resolve DISTINCT/GROUP
BY/ORDER BY. Both of these are inapplicable when the WITH
ROLLUP modifier is present.
Fixed by disabling the said optimizations for the WITH ROLLUP
case.
mysql-test/r/olap.result:
Added a test case for bug #48475.
mysql-test/t/olap.test:
Added a test case for bug #48475.
sql/sql_select.cc:
Disabled const-only table optimizations for the WITH ROLLUP
case.
only const tables
The problem was caused by two shortcuts in the optimizer that
are inapplicable in the ROLLUP case.
Normally in a case when only const tables are involved in a
query, DISTINCT clause can be safely optimized away since there
may be only one row produced by the join. Similarly, we don't
need to create a temporary table to resolve DISTINCT/GROUP
BY/ORDER BY. Both of these are inapplicable when the WITH
ROLLUP modifier is present.
Fixed by disabling the said optimizations for the WITH ROLLUP
case.
Bug#41756 "Strange error messages about locks from InnoDB".
In JT_EQ_REF (join_read_key()) access method,
don't try to unlock rows in the handler, unless certain that
a) they were locked
b) they are not used.
Unlocking of rows is done by the logic of the nested join loop,
and is unaware of the possible caching that the access method may
have. This could lead to double unlocking, when a row
was unlocked first after reading into the cache, and then
when taken from cache, as well as to unlocking of rows which
were actually used (but taken from cache).
Delegate part of the unlocking logic to the access method,
and in JT_EQ_REF count how many times a record was actually
used in the join. Unlock it only if it's usage count is 0.
Implemented review comments.
mysql-test/r/innodb_lock_wait_timeout_1.result:
Update results (Bug41756).
mysql-test/t/innodb_lock_wait_timeout_1.test:
Add a test case (Bug#41756).
sql/item_subselect.cc:
Complete struct READ_RECORD initialization with a new
member to unlock records.
sql/records.cc:
Extend READ_RECORD API with a method to unlock read records.
sql/sql_select.cc:
In JT_EQ_REF (join_read_key()) access method,
don't try to unlock rows in the handler, unless certain that
a) they were locked
b) they are not used.
sql/sql_select.h:
Add members to TABLE_REF to count TABLE_REF buffer usage count.
sql/structs.h:
Update declarations.
Bug#41756 "Strange error messages about locks from InnoDB".
In JT_EQ_REF (join_read_key()) access method,
don't try to unlock rows in the handler, unless certain that
a) they were locked
b) they are not used.
Unlocking of rows is done by the logic of the nested join loop,
and is unaware of the possible caching that the access method may
have. This could lead to double unlocking, when a row
was unlocked first after reading into the cache, and then
when taken from cache, as well as to unlocking of rows which
were actually used (but taken from cache).
Delegate part of the unlocking logic to the access method,
and in JT_EQ_REF count how many times a record was actually
used in the join. Unlock it only if it's usage count is 0.
Implemented review comments.
Bug#41756 "Strange error messages about locks from InnoDB".
In JT_EQ_REF (join_read_key()) access method,
don't try to unlock rows in the handler, unless certain that
a) they were locked
b) they are not used.
Unlocking of rows is done by the logic of the nested join loop,
and is unaware of the possible caching that the access method may
have. This could lead to double unlocking, when a row
was unlocked first after reading into the cache, and then
when taken from cache, as well as to unlocking of rows which
were actually used (but taken from cache).
Delegate part of the unlocking logic to the access method,
and in JT_EQ_REF count how many times a record was actually
used in the join. Unlock it only if it's usage count is 0.
Implemented review comments.
mysql-test/r/bug41756.result:
Add result file (Bug#41756)
mysql-test/t/bug41756-master.opt:
Use --innodb-locks-unsafe-for-binlog, as in 5.0 just
using read_committed isolation is not sufficient to
reproduce the bug.
mysql-test/t/bug41756.test:
Add a test file (Bug#41756)
sql/item_subselect.cc:
Complete struct READ_RECORD initialization with a new
member to unlock records.
sql/records.cc:
Extend READ_RECORD API with a method to unlock read records.
sql/sql_select.cc:
In JT_EQ_REF (join_read_key()) access method,
don't try to unlock rows in the handler, unless certain that
a) they were locked
b) they are not used.
sql/sql_select.h:
Add members to TABLE_REF to count TABLE_REF buffer usage count.
sql/structs.h:
Update declarations.
Bug#41756 "Strange error messages about locks from InnoDB".
In JT_EQ_REF (join_read_key()) access method,
don't try to unlock rows in the handler, unless certain that
a) they were locked
b) they are not used.
Unlocking of rows is done by the logic of the nested join loop,
and is unaware of the possible caching that the access method may
have. This could lead to double unlocking, when a row
was unlocked first after reading into the cache, and then
when taken from cache, as well as to unlocking of rows which
were actually used (but taken from cache).
Delegate part of the unlocking logic to the access method,
and in JT_EQ_REF count how many times a record was actually
used in the join. Unlock it only if it's usage count is 0.
Implemented review comments.
For application compatibility reasons MySQL converts "<autoincrement_column> IS NULL"
predicates to "<autoincrement_column> = LAST_INSERT_ID()" in the first SELECT following an
INSERT regardless of whether they're top level predicates or not. This causes wrong and
obscure results when these predicates are combined with others on the same columns. Fixed
by only doing the transformation on a single top-level predicate if a special SQL mode is
turned on (sql_auto_is_null).
Also made sql_auto_is_null off by default.
per-file comments:
mysql-test/r/func_isnull.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
test result updated
mysql-test/t/func_isnull.test
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
test case added
sql/mysqld.cc
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
sql_auto_is_null now is OFF by default.
sql/sql_select.cc
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
remove_eq_conds() split in two parts - one only checks the upper condition,
the req_remove_eq_conds() recursively checks all the condition tree.
mysql-test/extra/rpl_tests/rpl_insert_id.test
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
test fixed (set the sql_auto_is_null variable)
mysql-test/r/mysqlbinlog.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
result updated
mysql-test/r/mysqlbinlog2.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
result updated
mysql-test/r/odbc.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
result updated
mysql-test/r/query_cache.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
result updated
mysql-test/r/user_var-binlog.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
result updated
mysql-test/suite/binlog/r/binlog_row_ctype_ucs.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
result updated
mysql-test/suite/binlog/r/binlog_stm_ctype_ucs.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
result updated
mysql-test/suite/rpl/r/rpl_insert_id.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
result updated
mysql-test/suite/rpl/r/rpl_row_mysqlbinlog.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
result updated
mysql-test/suite/rpl/r/rpl_sp.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
result updated
mysql-test/t/odbc.test
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
test fixed (set the sql_auto_is_null variable)
For application compatibility reasons MySQL converts "<autoincrement_column> IS NULL"
predicates to "<autoincrement_column> = LAST_INSERT_ID()" in the first SELECT following an
INSERT regardless of whether they're top level predicates or not. This causes wrong and
obscure results when these predicates are combined with others on the same columns. Fixed
by only doing the transformation on a single top-level predicate if a special SQL mode is
turned on (sql_auto_is_null).
Also made sql_auto_is_null off by default.
per-file comments:
mysql-test/r/func_isnull.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
test result updated
mysql-test/t/func_isnull.test
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
test case added
sql/mysqld.cc
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
sql_auto_is_null now is OFF by default.
sql/sql_select.cc
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
remove_eq_conds() split in two parts - one only checks the upper condition,
the req_remove_eq_conds() recursively checks all the condition tree.
mysql-test/extra/rpl_tests/rpl_insert_id.test
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
test fixed (set the sql_auto_is_null variable)
mysql-test/r/mysqlbinlog.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
result updated
mysql-test/r/mysqlbinlog2.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
result updated
mysql-test/r/odbc.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
result updated
mysql-test/r/query_cache.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
result updated
mysql-test/r/user_var-binlog.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
result updated
mysql-test/suite/binlog/r/binlog_row_ctype_ucs.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
result updated
mysql-test/suite/binlog/r/binlog_stm_ctype_ucs.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
result updated
mysql-test/suite/rpl/r/rpl_insert_id.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
result updated
mysql-test/suite/rpl/r/rpl_row_mysqlbinlog.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
result updated
mysql-test/suite/rpl/r/rpl_sp.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
result updated
mysql-test/t/odbc.test
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
test fixed (set the sql_auto_is_null variable)
with temporary tables
There were two problems the test case from this bug was
triggering:
1. JOIN::rollup_init() was supposed to wrap all constant Items
into another object for queries with the WITH ROLLUP modifier
to ensure they are never considered as constants and therefore
are written into temporary tables if the optimizer chooses to
employ them for DISTINCT/GROUP BY handling.
However, JOIN::rollup_init() was called before
make_join_statistics(), so Items corresponding to fields in
const tables could not be handled as intended, which was
causing all kinds of problems later in the query execution. In
particular, create_tmp_table() assumed all constant items
except "hidden" ones to be removed earlier by remove_const()
which led to improperly initialized Field objects for the
temporary table being created. This is what was causing crashes
and valgrind errors in storage engines.
2. Even when the above problem had been fixed, the query from
the test case produced incorrect results due to some
DISTINCT/GROUP BY optimizations being performed by the
optimizer that are inapplicable in the WITH ROLLUP case.
Fixed by disabling inapplicable DISTINCT/GROUP BY optimizations
when the WITH ROLLUP modifier is present, and splitting the
const-wrapping part of JOIN::rollup_init() into a separate
method which is now invoked after make_join_statistics() when
the const tables are already known.
mysql-test/r/olap.result:
Added a test case for bug #48131.
mysql-test/t/olap.test:
Added a test case for bug #48131.
sql/sql_select.cc:
1. Disabled inapplicable DISTINCT/GROUP BY optimizations when
the WITH ROLLUP modifier is present.
2. Split the const-wrapping part of JOIN::rollup_init() into a
separate method.
sql/sql_select.h:
Added rollup_process_const_fields() declaration.
with temporary tables
There were two problems the test case from this bug was
triggering:
1. JOIN::rollup_init() was supposed to wrap all constant Items
into another object for queries with the WITH ROLLUP modifier
to ensure they are never considered as constants and therefore
are written into temporary tables if the optimizer chooses to
employ them for DISTINCT/GROUP BY handling.
However, JOIN::rollup_init() was called before
make_join_statistics(), so Items corresponding to fields in
const tables could not be handled as intended, which was
causing all kinds of problems later in the query execution. In
particular, create_tmp_table() assumed all constant items
except "hidden" ones to be removed earlier by remove_const()
which led to improperly initialized Field objects for the
temporary table being created. This is what was causing crashes
and valgrind errors in storage engines.
2. Even when the above problem had been fixed, the query from
the test case produced incorrect results due to some
DISTINCT/GROUP BY optimizations being performed by the
optimizer that are inapplicable in the WITH ROLLUP case.
Fixed by disabling inapplicable DISTINCT/GROUP BY optimizations
when the WITH ROLLUP modifier is present, and splitting the
const-wrapping part of JOIN::rollup_init() into a separate
method which is now invoked after make_join_statistics() when
the const tables are already known.
subquery returning multiple rows
Error handling was missing when handling subqueires in WHERE
and when assigning a SELECT result to a @variable.
This caused crash(es).
Fixed by adding error handling code to both the WHERE
condition evaluation and to assignment to an @variable.
subquery returning multiple rows
Error handling was missing when handling subqueires in WHERE
and when assigning a SELECT result to a @variable.
This caused crash(es).
Fixed by adding error handling code to both the WHERE
condition evaluation and to assignment to an @variable.
