Bug #20662 "Infinite loop in CREATE TABLE IF NOT EXISTS ... SELECT
with locked tables"
Bug #20903 "Crash when using CREATE TABLE .. SELECT and triggers"
Bug #24738 "CREATE TABLE ... SELECT is not isolated properly"
Bug #24508 "Inconsistent results of CREATE TABLE ... SELECT when
temporary table exists"
Deadlock occured when one tried to execute CREATE TABLE IF NOT
EXISTS ... SELECT statement under LOCK TABLES which held
read lock on target table.
Attempt to execute the same statement for already existing
target table with triggers caused server crashes.
Also concurrent execution of CREATE TABLE ... SELECT statement
and other statements involving target table suffered from
various races (some of which might've led to deadlocks).
Finally, attempt to execute CREATE TABLE ... SELECT in case
when a temporary table with same name was already present
led to the insertion of data into this temporary table and
creation of empty non-temporary table.
All above problems stemmed from the old implementation of CREATE
TABLE ... SELECT in which we created, opened and locked target
table without any special protection in a separate step and not
with the rest of tables used by this statement.
This underminded deadlock-avoidance approach used in server
and created window for races. It also excluded target table
from prelocking causing problems with trigger execution.
The patch solves these problems by implementing new approach to
handling of CREATE TABLE ... SELECT for base tables.
We try to open and lock table to be created at the same time as
the rest of tables used by this statement. If such table does not
exist at this moment we create and place in the table cache special
placeholder for it which prevents its creation or any other usage
by other threads.
We still use old approach for creation of temporary tables.
Also note that we decided to postpone introduction of some tests
for concurrent behaviour of CREATE TABLE ... SELECT till 5.1.
The main reason for this is absence in 5.0 ability to set @@debug
variable at runtime, which can be circumvented only by using several
test files with individual .opt files. Since the latter is likely
to slowdown test-suite unnecessary we chose not to push this tests
into 5.0, but run them manually for this version and later push
their optimized version into 5.1
- Queries in the query cache are identified by the individual
characters in the query statement, the current database and
the current environment expressed as a set of system variable
flags.
- Since the set of environment flags didn't properly describe the
current environment unexpected results were returned from the
query cache.
- Query cache is now cleared when the variable ft_boolean_syntax is
updated.
- An identification flag for the variable default_week_format is
added to the query cache record.
Thanks to Martin Friebe who has supplied significant parts of this patch.
- In some cases, flow control optimization implemented in sp::optimize
removes hreturn instructions, causing SQL exception handlers to:
* never return
* execute wrong logic
- This patch overrides default short cut optimization on hreturn instructions
to avoid this problem.
mysqldump didn't properly handle getting no data on
SHOW CREATE PROCEDURE. If S/C/P fails (due to dumping
user's insufficient privileges on mysql.proc, say),
mysqldump will print a comment to that effect to the
output and return an error-code. If the -f (force) option
is used, the dump will continue, otherwise, it will abort
right there and then.
Also fixes Bug#22761, "mysqldump reports no errors when using
--routines without mysql.proc privileges"
---
Merge tnurnberg@bk-internal.mysql.com:/home/bk/mysql-5.0-maint
into mysql.com:/home/tnurnberg/27293/50-27293
some rollup rows (rows with NULLs for grouping attributes) if GROUP BY
list contained constant expressions.
This happened because the results of constant expressions were not put
in the temporary table used for duplicate elimination. In fact a constant
item from the GROUP BY list of a ROLLUP query can be replaced for an
Item_null_result object when a rollup row is produced .
Now the JOIN::rollup_init function wraps any constant item referenced in
the GROYP BY list of a ROLLUP query into an Item_func object of a special
class that is never detected as constant item. This ensures creation of
fields for such constant items in temporary tables and guarantees right
results when the result of the rollup operation first has to be written
into a temporary table, e.g. in the cases when duplicate elimination is
required.
INSERT...ON DUPLICATE KEY UPDATE may cause error 1032:
"Can't find record in ..." if we are inserting into
InnoDB table unique index of partial key with
underlying UTF-8 string field.
This error occurs because INSERT...ON DUPLICATE uses a wrong
procedure to copy string fields of multi-byte character sets
for index search.
This bug occurs when error message length exceeds allowed limit: my_error()
function outputs "%s" sequences instead of long string arguments.
Formats like %-.64s are very common in errmsg.txt files, however my_error()
function simply ignores precision of those formats.
- unsigned flag was not handled correctly for a number of mathematical funcions, which led to incorrect results
- passing large values as the number of decimals to ROUND() resulted in incorrect results and even server crashes in some cases
- reverted the fix and the testcase for bug #10083 as it violates the manual
- fixed some testcases which relied on broken ROUND() behavior
