Also wouldn't a binary index be of use here to keep it small if you have a lot of records?
Fred On Sat, Jul 20, 2013 at 4:07 AM, Ted Roche <[email protected]> wrote: > On Sat, Jul 20, 2013 at 5:50 AM, Paul Hill <[email protected]> > wrote: > > > > > Be careful with this. Deleted() only has 2 possible values and 90% of > > your records will be false. > > > > This is absolutely true. A two-value index is normally not very useful, as > it is not very selective. > > HOWEVER, DELETED() is a special case. If DELETED ON, FoxPro will only > return records which do not have the hidden deleted column set. The only > way FoxPro can do this is to physically scan all of the affected records in > the table, an I/O intensive operation that defeats the key premise of > Rushmore: that the result set can be determined purely by reading the > indexes. > > > > This means your index tree will be non-optimal. > > > > The world is non-optimal. But we try our best. It is a compromise of > compromises. > > It could actually slow things down. > > > > That's THE key point. You need to test with YOUR data, on YOUR network, > with YOUR application, configuration, network traffic, etc. In theory, > theory and practice are the same. In practice, well.... > > -- > Ted Roche > Ted Roche & Associates, LLC > http://www.tedroche.com > > > --- StripMime Report -- processed MIME parts --- > multipart/alternative > text/plain (text body -- kept) > text/html > --- > [excessive quoting removed by server] _______________________________________________ Post Messages to: [email protected] Subscription Maintenance: http://mail.leafe.com/mailman/listinfo/profox OT-free version of this list: http://mail.leafe.com/mailman/listinfo/profoxtech Searchable Archive: http://leafe.com/archives/search/profox This message: http://leafe.com/archives/byMID/profox/CAJCBksqGDiam4MYp_OcpqYkxiCV3u32oKcaLOf5FcANve=j...@mail.gmail.com ** 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.
