Loading large tables with Unique Keys

MySQL & MariaDB Other MySQL® Questions
1

This subject resurrects the trick shown in this thread for loading or altering large tables.

Alter table performance with MyISAM

I am struggling with some random cases where the REPAIR TABLE process is showing “Repair with keycache” instead of “Repair by sorting”. In my latest test, on try # 2 it is “Repair by Sorting” which I believe is desired. Note that I use the “QUICK” option of the REPAIR TABLE command.

What would cause this to go into “Repair with keycache”?

Thanks,

johndz

2

Unique indexes are always rebuilt with the key cache, not by sort.