"Eric Bergen" <[EMAIL PROTECTED]> wrote in message news:[EMAIL PROTECTED] > When you add that index are more than 30% of the rows in the table > DateTimeNext>1126215680?
There are currently 28.53% of the rows that have "DateTimeNext>1126215680" Does this mean something of interest? If so, what? Thanks DanB > Dan Baker wrote: > >>I have lots of tables that are similar in nature: >> >>id int(11) PRI NULL auto_increment >>Name varchar(30) >>DateTimeNext int(11) >> >>The "DateTimeNext" field represents when this records needs attention. A >>value of zero indicates it is being ignored. There are times when *lots* >>of records DateTimeNext values will be zero. >> >>I want to find all records in the database that need attention today, so a >>typical query looks like: >>SELECT id,Name FROM tbl WHERE DateTimeNext>1126215680 >> >>When I EXPLAIN this query, I get the following: >> table type possible_keys key key_len ref rows Extra >> Site, ALL, NULL,NULL, NULL, NULL, 53587,Using where >> >>If I add an index for "DateTimeNext", the EXPLAIN shows: >> table type possible_keys key key_len ref rows Extra >> Site,ALL,DateTimeNext,NULL,NULL,NULL,53587,Using where >> >>It appears that the index does NO good in this query. >>Is there anything I can do to optimize this query? Alter the table to >>improve the query? Do anything to not scan the entire stinkin' table? >> >>Thank you, >>DanB -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
