great. thx! On 4/17/07, Daniel Kasak <[EMAIL PROTECTED]> wrote:
Arun Kumar PG wrote: > Guys, > > I know this is a stupid thing but I wanted to know if we have an index > on a > column "X" and if i have a query having 10000 OR conditions on the > field e.g. > where X=10 OR x=12 OR x=13 OR x=15...... so on then will it give any > benefits in terms of speed? Yes the index still works. I construct queries that have a decent number of OR conditions ( I default mine to limit to 100 conditions, all on the primary key ), and I get very good performance ( not only from MySQL, by the way, this seems to work on a number of different DB servers ). Keep in mind the max_packet_size for MySQL ( I think this is the one to watch anyway ). If your query exceeds this size, you're in trouble. Just for interest, I tried pushing my default to 10,000, then 20,000, and I still get amazingly good performance. Cool :) The reason I default to 100 is so I get decent performance across slow network connections ( eg DSL ). -- Daniel Kasak IT Developer NUS Consulting Group Level 5, 77 Pacific Highway North Sydney, NSW, Australia 2060 T: (+61) 2 9922-7676 / F: (+61) 2 9922 7989 email: [EMAIL PROTECTED] website: http://www.nusconsulting.com.au
