The problem reported is a compile bug,
reported by the development GCC team with GCC 4.2.
The original issue can no longer be reproduced in MySQL 5.1,
since the configure script no longer define HAVE_ATOMIC_ADD,
which caused the Linux atomic functions to be used (and cause a problem
with an invalid cast).
This patch implements some code cleanup for 5.1 only, which was identified
during the investigation of this issue.
With this patch, statistics maintained in THD::status_var are by definition
owned by the running thread, and do not need to be protected against race
conditions. These statistics are maintained by the status_var_* helpers,
which do not require any lock.
When processing the USE/FORCE index hints
the optimizer was not checking if the indexes
specified are enabled (see ALTER TABLE).
Fixed by:
Backporting the fix for bug 20604 to 5.0
mode.
When a new DATE/DATETIME field without default value is being added by the
ALTER TABLE the '0000-00-00' value is used as the default one. But it wasn't
checked whether such value was allowed by the set sql mode. Due to this
'0000-00-00' values was allowed for DATE/DATETIME fields even in the
NO_ZERO_DATE mode.
Now the mysql_alter_table() function checks whether the '0000-00-00' value
is allowed for DATE/DATETIME fields by the set sql mode.
The new error_if_not_empty flag is used in the mysql_alter_table() function
to indicate that it should abort if the table being altered isn't empty.
The new new_datetime_field field is used in the mysql_alter_table() function
for error throwing purposes.
The new error_if_not_empty parameter is added to the copy_data_between_tables()
function to indicate the it should return error if the source table isn't empty.
Uninitialized in the constructor member variables were
pointing to nirvana and causing a crash when debug information
of the Event Scheduler was dumped in result to COM_DEBUG
packet sent to the server.
my_decimal in some cases can contain more decimal digits than
is officially supported (DECIMAL_MAX_PRECISION), so we need to
prepare bigger buffer for the resulting string.
and invalidation in the most general case (non-temporary table and
not simple RENAME or ENABLE/DISABLE KEYS or partitioning command).
See comment for sql/sql_table.cc for more information.
These changes are prerequisite for 5.1 version of fix for bug #23667
"CREATE TABLE LIKE is not isolated from alteration by other connections"
UDF can be created from any library in any part of the server
LD_LIBRARY_PATH.
Allow to load udfs only from plugin_dir.
On windows, refuse to open udf in case it's path contains a slash.
No good test case for this bug because of imperfect error message
that includes error code and error string when it fails to dlopen a
library.
- Adding variable m_cached_result_type to keep the variable type consistent
during the execution of a statement.
- Before each result set is returned to the client the description of each
column is sent as meta data.
Previously the result type for a column could change if the hash variable
entry changed between statements. This caused the result set of the query
to alternate column types in certain cases which is not supported by MySQL
client-server protocol. Example:
Previously this sequence:
SET @a:=1;
SELECT @a:="text", @a;
would return "text", "text";
After the change the SELECT returns "text", 0
The reson for this is that previously the result set from 'SELECT @a;'
would always be of the type STRING, whereas now the type of the variable
is taken from the last SET statement. However, 'SELECT @a:="text"' will
return type of STRING since the right side of the assignment is used.
Problem: we may get syntactically incorrect queries in the binary log
if we use a string value user variable executing a PS which
contains '... limit ?' clause, e.g.
prepare s from "select 1 limit ?";
set @a='qwe'; execute s using @a;
Fix: raise an error in such cases.
