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.
Without this patch, all file elements in info have symlink resolved
pathnames. This means append_create_info does not have any way
of showing the correct database name when a symlinked database is used.
HEAP: Copies the key count to a backup variable and sets the key count to zero.
That way, no HEAP function will ever try to touch any index.
Re-enabling is done by copying back the backup variable.
To avoid memory leak at table close, disable deletes all index trees.
Re-enabling must be done with empty indexes and data anyway. Otherwise,
the indexes would need to be repaired, wich HEAP is not capable of.
MyISAM: Only the key_map is cleared and set.
Re-enabling must be done with empty indexes and data. Otherwise, repair needs
to be done which will enable all keys persistently.
The former implementation disabled only non-unique keys and maked this persistent.
The new implementation additionally can disable all keys, but only without
making this persistent. Re-enabling all keys can be done without repair,
if data file and indexes are empty.
Fixed problem with char > 128 in QUOTE() function. (Bug #1868)
Disable creation of symlinks if my_disable_symlink is set
Fixed searching of TEXT with end space. (Bug #1651)
Fixed caching bug in multi-table-update where same table was used twice. (Bug #1711)
Fixed problem with UNIX_TIMESTAMP() for timestamps close to 0. (Bug #1998)
Fixed timestamp.test
New multi-key-cache handling. This was needed becasue the old one didn't work reliable with MERGE tables.
ALTER TABLE table_name ... CHARACTER SET ... now changes all char/varchar/text columns to the given character set
(One must use ALTER TABLE ... DEFAULT CHARACTER SET ... to change the default character set)
Fixed that have_compress is detected properly (fixes problems with func_compress.test on platforms without zlib)
New syntax for CACHE INDEX ('keys' is optional if no index name is given and one mentions the key cache name only ones)
Removed compiler warnings
Added mysql_set_server_option() to allow clients like PHP to easaily set/reset the multi-statement flag.
Add pack_bits to pack_reclength for dynamic rows. This solves buffer a possible buffer overflow on update.
(This will probably solve bug #563)
Fix test for available file descriptors in mysqltest
Fixed core dump bug in replication tests when running without transactional table support
Fix for LEFT/RIGHT/MID with multi-byte-character sets (bug 314)
Fix for new bison 1.875
max_insert_delayed_threads and delayed_insert_timeout now works as documented (bug 211)
Don't show port in SHOW PROCESSLIST for system threads
Fix problem with ORDER BY being discarded for some DISTINCT queries (bug 275)
Fixed bug with NATURAL LEFT JOIN, NATURAL RIGHT JOIN and RIGHT JOIN when
using many joined tables (Bug 212)
Free row buffer cache after each query for MyISAM tables.
Added table join option FORCE INDEX
Fixed core dump bug when connecting with hostname that could not be resolved.