myisam tables
Queries following TRUNCATE of partitioned MyISAM table
may crash server if myisam_use_mmap is true.
Internally this is MyISAM bug, but limited to partitioned
tables, because MyISAM doesn't use ::delete_all_rows()
method for TRUNCATE, but goes via table recreate instead.
MyISAM didn't properly fall back to non-mmaped I/O after
mmap() failure. Was not repeatable on linux before, likely
because (quote from man mmap):
SUSv3 specifies that mmap() should fail if length is 0.
However, in kernels before 2.6.12, mmap() succeeded in
this case: no mapping was created and the call returned
addr. Since kernel 2.6.12, mmap() fails with the error
EINVAL for this case.
The task is to
(a) add a comment on indexes and
(b) increase the maximum length of column, table and the new index comments.
The patch committed on behalf of Yoshinori Matsunobu (Yoshinori.Matsunobu@Sun.COM).
Bug#40181 Made use of tdc_remove_table instead of just
setting share->version to 0 to make sure all unused table
instances go away as part of CREATE/ALTER TABLE.
ONLY_FULL_GROUP_BY
Problem was that during checking and preparation of the
partitioining function as a side effect in fix_fields
the full_group_by_flag was changed.
Solution was to set it back to its original value after
calling fix_fields.
Updated patch, to also exclude allow_sum_func from being
affected of fix_fields, as requested by reviewer.
backport for bug#44059 from mysql-pe to mysql-5.1-bugteam
Using the partition with most rows instead of first partition
to estimate the cardinality of indexes.
INSERT ... SELECT ...
Problem was that when bulk insert is used on an empty
table/partition, it disables the indexes for better
performance, but in this specific case it also tries
to read from that partition using an index, which is
not possible since it has been disabled.
Solution was to allow index reads on disabled indexes
if there are no records.
Also reverted the patch for bug#38005, since that was a workaround
in the partitioning engine instead of a fix in myisam.
when partition is reoganized.
Problem was that table->timestamp_field_type was not changed
before copying rows between partitions.
fixed by setting it to TIMESTAMP_NO_AUTO_SET as the first thing
in fast_alter_partition_table, so that all if-branches is covered.
column on partitioned table
An assertion 'ASSERT_COULUMN_MARKED_FOR_READ' is failed if the query
is executed with index containing double column on partitioned table.
The problem is that assertion expects all the fields which are read,
to be in the read_set.
In this query only the field 'a' is in the readset as the tables in
the query are joined by the field 'a' and so the assertion fails
expecting other field 'b'.
Since the function cmp() is just comparison of two parameters passed,
the assertion is not required.
Fixed by removing the assertion in the double fields comparision
function and also fixed the index initialization to do ordered
index scan with RW LOCK which ensures all the fields from a key are in
the read_set.
Note: this bug is not reproducible with other datatypes because the
assertion doesn't exist in comparision function for other
datatypes.
We disallow the partitioning of a log table. You could however
partition a table first, and then point logging to it. This is
not only against the docs, it also crashes the server.
We catch this case now.
contains ONLY_FULL_GROUP_BY
The partitioning code needs to issue a Item::fix_fields()
on the partitioning expression in order to prepare
it for being evaluated.
It does this by creating a special table and a table list
for the scope of the partitioning expression.
But when checking ONLY_FULL_GROUP_BY the
Item_field::fix_fields() was relying that there always be
cached_table set and was trying to use it to get the
select_lex of the SELECT the field's table is in.
But the cached_table was not set by the partitioning code
that creates the artificial TABLE_LIST used to resolve the
partitioning expression and this resulted in a crash.
Fixed by rectifying the following errors :
1. Item_field::fix_fields() : the code that check for
ONLY_FULL_GROUP_BY relies on having tables with
cacheable_table set. This is mostly true, the only
two exceptions being the partitioning context table
and the trigger context table.
Fixed by taking the current parsing context if no pointer
to the TABLE_LIST instance is present in the cached_table.
2. fix_fields_part_func() :
2a. The code that adds the table being created to the
scope for the partitioning expression is mostly a copy
of the add_table_to_list and friends with one exception :
it was not marking the table as cacheable (something that
normal add_table_to_list is doing). This caused the
problem in the check for ONLY_FULL_GROUP_BY in
Item_field::fix_fields() to appear.
Fixed by setting the correct members to make the table
cacheable.
The ideal structural fix for this is to use a unified
interface for adding a table to a table list
(add_table_to_list?) : noted in a TODO comment
2b. The Item::fix_fields() was called with a NULL destination
pointer. This causes uninitalized memory reads in the
overloaded ::fix_fields() function (namely
Item_field::fix_fields()) as it expects a non-zero pointer
there. Fixed by passing the source pointer similarly to how
it's done in JOIN::prepare().
Backport from 6.0
Changed error message to show that it is partitioning
that does not support foreign keys yet.
Changed spelling from British english to American english.
become unescaped
Problem was only with the print out of the KEY partitioning list of
fields, it did not include quotes, even if it was needed.
Fixed by always add quotes if needed.
Problem: Many test cases don't clean up after themselves (fail
to drop tables or fail to reset variables). This implies that:
(1) check-testcase in the new mtr that currently lives in
5.1-rpl failed. (2) it may cause unexpected results in
subsequent tests.
Fix: make all tests clean up.
Also: cleaned away unnecessary output in rpl_packet.result
Also: fixed bug where rpl_log called RESET MASTER with a running
slave. This is not supposed to work.
Also: removed unnecessary code from rpl_stm_EE_err2 and made it
verify that an error occurred.
Also: removed unnecessary code from rpl_ndb_ctype_ucs2_def.
order by
Problem was that the first index read was unordered,
and the next was ordered, resulting in use of
uninitialized data.
Solution was to use the correct variable to see if
the 'next' call should be ordered or not.
