Re: large table design / query performance

[Rick James]

There is no simple answer to your question. We really need a lot of specifics:

To assist in analyzing slow SELECTs, please provide
* SHOW CREATE TABLE tbl\G -- engine, indexes, character set
* SHOW TABLE STATUS LIKE 'tbl'\G -- sizes
* EXPLAIN SELECT ...\G -- clues of inefficiencies
and surround them with [ code ] and [ / code ]

Sure, VARCHARs are slower than INTs. But not enough to matter. The big time consumer in large tables is I/O, not fiddling with characters versus numbers. TIMESTAMP is internally the same as INT.

> Will an auto index integer primary key help

Maybe. But other things are more likely to help.

> or changing the database engine?

Maybe. InnoDB is preferred. Note: An InnoDB table must have a PRIMARY KEY.

What is the value of innodb_buffer_pool_size? How much RAM do you have?