Geoff Flight wrote: > Does random distribution truly speed up an index? I think so, because more potential matches can be eliminated with every step. For instance, a UUID of:
'0fc3616f-1548-4574-b277-0105d15f09b7' starts with '0', and there are 16 possibilities for each character. So in a randomly-generated UUID (which I use) in a million rows you'd expect about 62,500 records for each possibility in position 0. So just looking at position 0, you'd eliminate (1,000,000 - 62,500) rows from the candidates. You then look at position 1, and your set to consider isn't 1,000,000 rows but around 62,500 rows. 'f' occurs about 3907 times. Etc. etc. You may well find a unique row within only a few iterations like this. Paul _______________________________________________ Post Messages to: [email protected] Subscription Maintenance: http://leafe.com/mailman/listinfo/profox OT-free version of this list: http://leafe.com/mailman/listinfo/profoxtech Searchable Archive: http://leafe.com/archives/search/profox This message: http://leafe.com/archives/byMID/profox/[email protected] ** All postings, unless explicitly stated otherwise, are the opinions of the author, and do not constitute legal or medical advice. This statement is added to the messages for those lawyers who are too stupid to see the obvious.
