Question

I have a table where I want SELECT to have priority over INSERT, so i do LOW PRIORITY inserts;

I’ve read that locking the table with a READ LOCAL lock while reading from the table allows inserts to be made concurrently with reading in non-fragmented MyIsam tables (because it ads rows at the end of the table).

If i do the SELECTs with READ LOCAL lock and the INSERTs with LOW PRIORITY, does using LOW PRIORITY makes the INSERTs wait even if the READ LOCAL allows acces?

Answer 1

http://dev.mysql.com/doc/refman/5.5/en/insert.html

“Note that LOW_PRIORITY should normally not be used with MyISAM tables because doing so disables concurrent inserts”

In most cases INSERTs won’t block a SELECT in any noticeable way as inserts are usually very fast (especially with MyISAM) but complex SELECT queries can be quite slow.