Repair table could crash a server if there is not sufficient
memory (myisam_sort_buffer_size) to operate. Affects not only
repair, but also all statements that use create index by sort:
repair by sort, parallel repair, bulk insert.
Return an error if there is not sufficient memory to store at
least one key per BUFFPEK.
Also fixed memory leak if thr_find_all_keys returns an error.
OPTIMIZE TABLE with myisam_repair_threads > 1 performs a non-quick
parallel repair. This means that it does not only rebuild all
indexes, but also the data file.
Non-quick parallel repair works so that there is one thread per
index. The first of the threads rebuilds also the new data file.
The problem was that all threads shared the read io cache on the
old data file. If there were holes (deleted records) in the table,
the first thread skipped them, writing only contiguous, non-deleted
records to the new data file. Then it built the new index so that
its entries pointed to the correct record positions. But the other
threads didn't know the new record positions, but put the positions
from the old data file into the index.
The new design is so that there is a shared io cache which is filled
by the first thread (the data file writer) with the new contiguous
records and read by the other threads. Now they know the new record
positions.
Another problem was that for the parallel repair of compressed
tables a common bit_buff and rec_buff was used. I changed it so
that thread specific buffers are used for parallel repair.
A similar problem existed for checksum calculation. I made this
multi-thread safe too.
Though this is not storage engine specific problem, I was able to
repeat this problem with BDB and NDB engines only. That was the
reason to add a test case into ndb_update.test. As a result
different bad things could happen.
BDB has removed duplicate rows which is not expected.
NDB returns an error.
For multi table update notify storage engine about UPDATE IGNORE
as it is done in single table UPDATE.
Crash may happen when selecting from a merge table that has underlying
tables with less indexes than in a merge table itself.
If number of keys in merge table is not bigger than requested key number,
return error.
an ALL/ANY quantified subquery in HAVING.
The Item::split_sum_func2 method should not create Item_ref
for objects of any class derived from Item_subselect.
Item_substr's results are improperly stored in a temporary table due to
wrongly calculated max_length value for multi-byte charsets if two
arguments specified.
Any default value for a enum fields over UCS2 charsets was corrupted
when we put it into the frm file, as it had been overwritten by its
HEX representation.
To fix it now we save a copy of structure that represents the enum
type and when putting the default values we use this copy.
Fixed confusing error message from the storage engine when
it fails to open underlying table. The error message is issued
when a table is _opened_ (not when it is created).
statement that uses an aggregating IN subquery with
HAVING clause.
A wrong order of the call of split_sum_func2 for the HAVING
clause of the subquery and the transformation for the
subquery resulted in the creation of a andor structure
that could not be restored at an execution of the prepared
statement.
