Re: Alt index search on partitioned table

[Rick James]

If you have a separate column for the partition number, you could get it to do "pruning".

True, the current version of MySQL fails to touch all the partitions in parallel. That feature may be available in a year or so.

SHA1 (and any other digest) is a terribly way to index any huge table. It is very random, so the caching is virtually useless unless you have some rows that are frequently used.

Don't PARTITION unless you have over a million rows in the table.

EXPLAIN PARTITION SELECT ... to see if it does the pruning.

An AUTO_INCREMENT need not be declared UNIQUE or PRIMARY.

Why do you need to auto_inc if you have a SHA1?

Provide
SHOW CREATE TABLE
SELECT ...
so we can discuss the performance issues further.