Tuned the SQL optimizer to favor more often index searches over table scans.
Fixed a performance problem when several large SELECT queries are run concurrently on a multiprocessor Linux computer. Large CPU-bound SELECT queries will now also generally run faster on all platforms.
If MySQL binlogging is used, InnoDB now prints after crash recovery the latest MySQL binlog file name and the position in that file (= byte offset) InnoDB was able to recover to. This is useful, for example, when resynchronizing a master and a slave database in replication.
Added better error messages to help in installation problems.
One can now recover also MySQL temporary tables which have become orphaned inside the InnoDB tablespace.
InnoDB now prevents a FOREIGN KEY declaration where the signedness is not the same in the referencing and referenced integer columns.
Fixed a bug : calling SHOW CREATE TABLE or SHOW TABLE STATUS could cause memory corruption and make mysqld to crash. Especially at risk was mysqldump, because it calls frequently SHOW CREATE TABLE.
Fixed a bug : if on Unix you did an ALTER TABLE to an InnoDB table and simultaneously did queries to it, mysqld could crash with an assertion failure in row0row.c, line 474.
Fixed a bug : if inserts to several tables containing an auto-inc column were wrapped inside one LOCK TABLES, InnoDB asserted in lock0lock.c.
In 3.23.47 we allowed several NULLS in a UNIQUE secondary index. But CHECK TABLE was not relaxed: it reports the table as corrupt. CHECK TABLE no longer complains in this situation.
Fixed a bug : on Sparc and other high-endian processors SHOW VARIABLES showed innodb_flush_log_at_trx_commit and other boolean-valued startup parameters always OFF even if they were switched on.
Fixed a bug : if you ran mysqld-max-nt as a service on Windows NT/2000, the service shutdown did not always wait long enough for the InnoDB shutdown to finish.
This is a translation of the MySQL Reference Manual that can be found at dev.mysql.com. The original Reference Manual is in English, and this translation is not necessarily as up to date as the English version.