… not fit in cache well) When you want to run this query mysql first will try to find each … if there is one – it is often a lot faster to retrieve rows in order checking WHERE clause for … the most optimal. We do not really need separate subselect to make MySQL check WHERE clause while scanning table …
Post: Derived Tables and Views Performance
August 31, 2006 By 16 Comments
…what is called derived tables, inline views or basically subselects in the from clause. In MySQL 5.0 …, ie forgotten join condition you might have EXPLAIN running forever. Views on other hand do not have … will be faster in most cases. In many cases even separate temporary table will be faster as you …
Post: MySQL Query Cache
July 27, 2006 By 70 Comments
…example I’m using Query Cache on server which runs this blog. Updates are rather rare so per-… full queries only – Meaning it does not work for subselects, inline views, parts of the UNION. This is … you can enable query cache so it works faster. Low load applications – If you’re building application …
Post: Database problems in MySQL/PHP Applications
August 11, 2006 By 13 Comments
… used so using values generated elseware might be faster. 3. Using multiple databases Honestly I do not… this case. This most applies to subqueries Where Subselects with IN() become corellated even if they are …reasonable amount of data in it. And do run EXPLAIN for your queries, especially if you see…
Comment: Database problems in MySQL/PHP Applications
August 11, 2006 By 13 Comments
…used so using values generated elseware > might be faster. I disagree with you on this completely …this case. > This most applies to subqueries Where Subselects with IN() become > corellated even if they are …reasonable > amount of data in it. And do run EXPLAIN for your queries, especially > if you …
