On 21 Nov 2002, at 18:20, Hans Zaunere wrote: > > but as long as it's a DATETIME > > column then you are looking for a range of values, so 'range' is the > > best you're going to get in the EXPLAIN output. > > Yes, but the real data I'm looking for is not a range - it's simply a part of > a single value.
Any time you're looking for the first part of a column value, you're looking for a range. It's simply a special case of a range query. I don't see why you care what MySQL calls it, as long as you're getting an answer in a reasonable time. > In Oracle the DATE column type contains date and time information. However, > one can query only for the date, and Oracle will honor that as what it needs > to pick out of the column. I had hoped that MySQL would do the same, since > it looks like it stores the data in a very similar way. Maybe Oracle and MySQL are doing the same thing behind the curtain, or maybe they're not. I think you're obsessing too much about the type in the EXPLAIN output. The EXPLAIN output is just a diagnostic tool, not an end in itself. The important question is whether you're getting the correct result fast enough for your purposes. If so, then stop worrying. If not, then you may need to make some changes in your table structure (introduce a separate DATE column, or break the date and time into different columns). Yes, it might be nice if you could do something like "WHERE DATE_PART(thecolumn) = '2002-11-21'" and have MySQL use the index, but it would be doing exactly the same thing it does now when you say "WHERE thecolumn BETWEEN '2002-11-21 00:00:00' AND '2002-11-21 23:59:59'". There wouldn't be any difference in performance, just a different query syntax. But maybe I'm still misunderstanding your problem. -- Keith C. Ivey <[EMAIL PROTECTED]> Tobacco Documents Online http://tobaccodocuments.org Phone 202-667-6653 --------------------------------------------------------------------- Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
