NULL values are allowed in indexed columns. In cases of keys longer than 250 bytes, a bigger key block size than the default of 1024 bytes is used for this key. This can be enlarged to 64 without having to recompile myisamchk . Dynamic size rows will now be much less fragmented when mixing deletes with updates and inserts. This is done by automatically combining adjacent deleted blocks and by extending blocks if the next block is deleted.
All key segments have their own language definition.
This will enable MySQL to have different language definitions per column. Note that index files are usually much smaller with MyISAM than with ISAM . This means that MyISAM will normally use less system resources than ISAM , but will need more CPU when inserting data into a compressed index. The following options to mysqld can be used to change the behavior of MyISAM tables. See section 4.16.4 mysqld Command-line Options .