The optimizer pulls up aggregate functions which should be aggregated in
an outer select. At some point it may substitute such a function for a field
in the temporary table. The setup_copy_fields function doesn't take this
into account and may overrun the copy_field buffer.
Fixed by filtering out the fields referenced through the specialized
reference for aggregates (Item_aggregate_ref).
Added an assertion to make sure bugs that cause similar discrepancy
don't go undetected.
mysql-test-run.pl --start-and-exit starts but does not exit
Instead, it hangs with ActiveState perl. The error is
believed to be a bug in ActiveState implementation.
Workaround is using POSIX::_exit, as described here
http://www.perlmonks.org/?node_id=334610
Thanks to Philip Stoev for the idea of the patch.
The '@' symbol can not be used in the host name according to rfc952.
The fix:
added function check_host_name(LEX_STRING *str)
which checks that all symbols in host name string are valid and
host name length is not more than max host name length
(just moved check_string_length() function from the parser into check_host_name()).
The problem:
I_S views table does not check the presence of SHOW_VIEW_ACL|SELECT_ACL
privileges for a view. It leads to discrepancy between SHOW CREATE VIEW
and I_S.VIEWS.
The fix:
added appropriate check.
The Blackhole engine did not support row-based replication
since the delete_row(), update_row(), and the index and range
searching functions were not implemented.
This patch adds row-based replication support for the
Blackhole engine by implementing the two functions mentioned
above, and making the engine pretend that it has found the
correct row to delete or update when executed from the slave
SQL thread by implementing index and range searching functions.
It is necessary to only pretend this for the SQL thread, since
a SELECT executed on the Blackhole engine will otherwise never
return EOF, causing a livelock.
is inconsistent
+ several improvements
Details:
- The subtest with assignment of floating point numbers to
DECIMAL parameters in functions and procedures checks
now that the final DECIMAL value is the same as if we assign
the floating point numbers to columns, user variables etc.
= The impact of math libs or truncation must be the same.
- Remove storage engine variants of this test because the
stored procedure properties tested do not depend on
the storage engine.
Use the fastest storage engine (MEMORY) for any tables
needed.
- reset global sort_buffer_size to startup value
- Partially improved formatting.
When analyzing the possible index use cases the server was re-using an internal structure.
This is wrong, as this internal structure gets updated during the analysis.
Fixed by making a copy of the internal structure for every place it needs to be used.
Also stopped the generation of empty SEL_TREE structures that unnecessary
complicate the analysis.
Bug#37536: Thread scheduling causes performance degradation at low thread count
Deprecated --skip-thread-priority startup option as newer versions of
the server won't change the thread priorities by default.
Giving threads different priorities might yield marginal improvements
in some platforms (where it actually works) but on the other hand it
might cause significant degradation depending on the thread count and
number of processors. Meddling with the thread priorities is a not a
safe bet as it is very dependent on the behavior of the cpu scheduler
and system where MySQL is being run.
From MySQL 6.0 and up the default behavior is that of not modifying
the threads priorities.
This patch contains fixes for two problems:
1. As originally reported, the server crashed on Mac OS X when trying to access
an EXAMPLE table after the EXAMPLE plugin was installed.
It turned out that the dynamically loaded EXAMPLE plugin called the
function hash_earch() from a Mac OS X system library, instead of
hash_earch() from MySQL's mysys library. Makefile.am in storage/example
does not include libmysys. So the Mac OS X linker arranged the hash_search()
function to be linked to the system library when the shared object is
loaded.
One possible solution would be to include libmysys into the linkage of
dynamic plugins. But then we must have a libmysys.so, which must be
used by the server too. This could have a minimal performance impact,
but foremost the change seems to bee too risky at the current state of
MySQL 5.1.
The selected solution is to rename MySQL's hash_search() to my_hash_search()
like it has been done before with hash_insert() and hash_reset().
Since this is the third time, we need to rename a hash_*() function,
I did renamed all hash_*() functions to my_hash_*().
To avoid changing a zillion calls to these functions, and announcing
this to hundreds of developers, I added defines that map the old names
to the new names.
This change is in hash.h and hash.c.
2. The other problem was improper implementation of the handlerton-to-plugin
mapping. We use a fixed-size array to hold a plugin reference for each
handlerton. On every install of a handler plugin, we allocated a new slot
of the array. On uninstall we did not free it. After some uninstall/install
cycles the array overflowed. We did not check for overflow.
One fix is to check for overflow to stop the crashes.
Another fix is to free the array slot at uninstall and search for a free slot
at plugin install.
This change is in handler.cc.
from stored procedure.
Problem: we replace all references to local variables in stored procedures
with NAME_CONST(name, value) logging to the binary log. However, if the
value's collation differs we might get an 'illegal mix of collation'
error as we don't pass the collation to the function.
Fix: pass the value's collation to NAME_CONST().
Note: actually we should pass to NAME_CONST() the value's derivation as well.
It's impossible without the parser modifying. Now we always set the
derivation to DERIVATION_IMPLICIT, the same as local variables have.
