with dependent subqueries
An IN subquery is executed on EXPLAIN when it's not correlated.
If the subquery required a temporary table for its execution
not all the internal structures were restored from pointing to
the items of the temporary table to point back to the items of
the subquery.
Fixed by restoring the ref array when a temp tables were used in
executing the IN subquery during EXPLAIN EXTENDED.
slave
The stored-routine code took the contents of the (lowest) parser
and copied it directly to the binlog, which causes problems if there
is a special case of interpretation at the parser level -- which
there is, in the "/*!VER */" comments. The trailing "*/" caused
errors on the slave, naturally.
Now, since by that point we have /properly/ created parse-tree (as
the rest of the server should do!) for the stored-routine CREATE, we
can construct a perfect statement from that information, instead of
writing uncertain information from an unknown parser state.
Fortunately, there's already a function nearby that does exactly
that.
---
Update for Bug#36570. Qualify routine names with db name when
writing to the binlog ONLY if the source text is qualified.
slave
The stored-routine code took the contents of the (lowest) parser
and copied it directly to the binlog, which causes problems if there
is a special case of interpretation at the parser level -- which
there is, in the "/*!VER */" comments. The trailing "*/" caused
errors on the slave, naturally.
Now, since by that point we have /properly/ created parse-tree (as
the rest of the server should do!) for the stored-routine CREATE, we
can construct a perfect statement from that information, instead of
writing uncertain information from an unknown parser state.
Fortunately, there's already a function nearby that does exactly
that.
with previous rows.
The WHERE clause containing expression:
CONCAT(empty_field1, empty_field2, ..., 'literal constant', ...)
REGEXP 'regular expression'
may return wrong matches.
Optimization of the CONCAT function has been fixed.
subselects into account
It is forbidden to use the SELECT INTO construction inside UNION statements
unless on the last SELECT of the union. The parser records whether it
has seen INTO or not when parsing a UNION statement. But if the INTO was
legally used in an outer query, an error is thrown if UNION is seen in a
subquery. Fixed in 5.0 by remembering the nesting level of INTO tokens and
mitigate the error unless it collides with the UNION.
When flushing tables, there were a slight chance that the flush was occuring
between processing of two table map events. Since the tables are opened
one by one, it might result in that the tables were not valid and that sub-
sequent locking of tables would cause the slave to crash.
The problem is solved by opening and locking all tables at once using
simple_open_n_lock_tables(). Also, the patch contain a change to open_tables()
so that pre-locking only takes place when the trg_event_map is not zero, which
was not the case before (this caused the lock to be placed in thd->locked_tables
instead of thd->lock since the assumption was that triggers would be called
later and therefore the tables should be pre-locked).
The REPAIR TABLE ... USE_FRM query silently corrupts data of tables
with old .FRM file version.
The mysql_upgrade client program or the REPAIR TABLE query (without
the USE_FRM clause) can't prevent this trouble, because in the
common case they don't upgrade .FRM file to compatible structure.
1. Evaluation of the REPAIR TABLE ... USE_FRM query has been
modified to reject such tables with the message:
"Failed repairing incompatible .FRM file".
2. REPAIR TABLE query (without USE_FRM clause) evaluation has been
modified to upgrade .FRM files to current version.
3. CHECK TABLE ... FOR UPGRADE query evaluation has been modified
to return error status when .FRM file has incompatible version.
4. mysql_upgrade and mysqlcheck client programs call CHECK TABLE
FOR UPGRADE and REPAIR TABLE queries, so their behaviors have
been changed too to upgrade .FRM files with incompatible
version numbers.
SHOW commands fail in embedded mode because schema_table array doesn't
correspond to enum_schema_tables.
This patch implements a dummy implementation of the abstract fill_table
function to be used when the event scheduler (or other core feature)
isn't part of the build.
The event scheduler was not designed to work in embedded mode. This
patch disables and excludes the event scheduler when the server is
compiled for embedded build.
Problem was that mysql_create_view did not remove all comments characters
when writing to binlog, resulting in parse error of stmt on slave side.
Solution was to use the recreated select clause
and add a generated CHECK OPTION clause if needed.
- Disable the "prefer full scan on clustered primary key over full scan
of any secondary key" rule introduced by BUG#35850.
- Update test results accordingly
(bk trigger: file this for BUG#35850)
or incorrect.
For better conformance with standard, truncation procedure of CHAR columns
has been changed to ignore truncation of trailing whitespace characters
(note has been removed).
Finally, for columns with non-binary charsets:
1. CHAR(N) columns silently ignore trailing whitespace truncation;
2. VARCHAR and TEXT columns issue Note about truncation.
BLOBs and other columns with BINARY charset are unaffected.
The bug is a regression introduced by the patch for bug32798.
The code in Item_func_group_concat::clear() relied on the 'distinct'
variable to check if 'unique_filter' was initialized. That, however,
is not always valid because Item_func_group_concat::setup() can do
shortcuts in some cases w/o initializing 'unique_filter'.
Fixed by checking the value of 'unique_filter' instead of 'distinct'
before dereferencing.
When a zero length is provided to the my_decimal_length_to_precision
function along with unsigned_flag set to false it returns a negative value.
For queries that employs temporary tables may cause failed assertion or
excessive memory consumption while temporary table creation.
Now the my_decimal_length_to_precision and the my_decimal_precision_to_length
functions take unsigned_flag into account only if the length/precision
argument is non-zero.
The function test_if_skip_sort_order ignored any covering index used for ref
access of a table in a query with ORDER BY if this index was incompatible
with the ORDER BY list and there was another covering index compatible with
this list.
As a result sub-optimal execution plans were chosen for some queries with
ORDER BY clause.
impossible WHERE/HAVING clause
(subselect_single_select_engine::exec).
Allocation and initialization of joined table list t1, t2... of
subqueries like:
NOT IN (SELECT ... FROM t1,t2,... WHERE 0)
is optimized out, however server tries to traverse this list.
