|Handler_read_rnd||61 k||The number of requests to read a row based on a fixed position. This is high if you are doing a lot of queries that require sorting of the result. You probably have a lot of queries that require MySQL to scan whole tables or you have joins that don't use keys properly.|
|Handler_read_rnd_next||13 M||The number of requests to read the next row in the data file. This is high if you are doing a lot of table scans. Generally this suggests that your tables are not properly indexed or that your queries are not written to take advantage of the indexes you have.|
|Select_full_join||1||The number of joins that do not use indexes. If this value is not 0, you should carefully check the indexes of your tables.|
These numbers grow quite quickly, and each indicates that there is a problem with indexing. When I performed the upgrade to 1.7, the site slowed to a crawl and I discovered a missing index in the log table. Now it appears like I may be missing a few more indexes.
I'm not sure where to go from here. If I am missing indexes, how can I go about discovering which ones?
Any advice much appreciated!