Incorrect key file with MySQL

Question

I\'m having a problem with a InnoDB (table was initally MyISAM, but converted it to InndoB awhile ago) table; I am trying to run this query:

SELECT 
   posts         


        

Answer 1

What's going on here is MySQL is doing the ORDER BY by building a temporary table from the join of the two tables. The temporary table is too large to fit into memory so MySQL creates a temporary file.

There are a few thing that would prevent this from working correctly. Raw disk space is one. ulimit is another. If this is being hosted, they may have a quota on your disk usage (in addition to ulimit).

I would suggest adding a limiting clause to your query. Currently you load the entire of both the rss_posts and rss_feeds into the temporary table for sorting. If you only want the most recent 10 that's a lot more data than you really need.

SELECT posts.id, posts.post_title 
FROM rss_posts AS posts INNER JOIN rss_feeds AS feeds ON posts.blog_id=feeds.id 
WHERE feeds.blog_language=1 
AND posts.post_data_db > (now - interval 30 day);
ORDER BY posts.post_date_db DESC LIMIT 10;