Creating a key will make that query execute very fast, but if that is the only reason for the key you are going to be trading quite a lot of space for the speed of one query.
How often are you going to run this query? If you have 324 million rows, then that index is going to consume somewhere in the order of 2G or more of disk space. Is it worth using all that space to make one query faster? --- J S <[EMAIL PROTECTED]> wrote: > Hi, > > I want to find the earliest and latest times in the > time column of my table > internet_usage: > > +--------------+----------------------+------+-----+---------+-------+ > | Field | Type | Null | Key | > Default | Extra | > +--------------+----------------------+------+-----+---------+-------+ > | uid | int(10) unsigned | | MUL | > 0 | | > | time | timestamp(14) | YES | | > NULL | | > | ip | int(10) unsigned | | | > 0 | | > | urlid | int(10) unsigned | | | > 0 | | > | timetaken | smallint(5) unsigned | YES | | > 0 | | > | cs_size | int(10) unsigned | YES | | > 0 | | > | sc_size | int(10) unsigned | YES | | > 0 | | > | method_ID | tinyint(3) unsigned | | | > 0 | | > | action_ID | tinyint(3) unsigned | | | > 0 | | > | virus_ID | tinyint(3) unsigned | | | > 0 | | > | useragent_ID | smallint(5) unsigned | | | > 0 | | > +--------------+----------------------+------+-----+---------+-------+ > > So far there are 324936160 rows. If I do : > > SELECT MIN(time) as earliest, MAX(time) as latest > from internet_usage; > > I can see the query is going to run for a long time. > Do I have to create an > index on time to speed this up or is there another > way of doing it? > > Thanks for any help. > > JS. > > _________________________________________________________________ > It's fast, it's easy and it's free. Get MSN > Messenger today! > http://www.msn.co.uk/messenger > > > -- > MySQL General Mailing List > For list archives: http://lists.mysql.com/mysql > To unsubscribe: > http://lists.mysql.com/[EMAIL PROTECTED] > > -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
