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INDEX ON DELETED??????
Message
From
21/11/1997 15:37:59
 
 
To
21/11/1997 15:23:06
General information
Forum:
Visual FoxPro
Category:
Other
Miscellaneous
Thread ID:
00061533
Message ID:
00061664
Views:
40
>>>>>I have a very large table containing approximately 5 million entries.
>>>>>It has always been stated that it is a good practice to create an
>>>>>index tag on DELETED(). However, when browsing a VFP 5.0
>>>>>table with this number of records the time to see the results
>>>>>is Very SLLLLOOOOOWWW.
>>>>>
>>>>>SQL queries also seem slower unless you SET DELETED OFF.
>>>>>If that global setting needs to be turned off to get performance
>>>>>what is the point.
>>>>>
>>>>>I have heard from one of if not the best FoxPro guru's that
>>>>>what is taking place is that the bitmap of the deleted tag will
>>>>>be copied to the users local PC. This truly appears to be the
>>>>>case when viewing the number of bytes being transfered
>>>>>across the network.
>>>>>
>>>>>Anyone else out there dealing with large tables with a deleted
>>>>>tag? Not sure the best approach. I know that the SYS(3054,11)
>>>>>function will not return a FULL optimization with an index tag.
>>>>>
>>>>>Your thoughts on this matter will be appreciated...
>>>>
>>>>DELETED() tag is necessary for most of people, and highly recommended for others :). With this tag you should get full optimization, if not then something else is wrong. Surely, SET DELETED OFF is radical cure to speed up queries, but in most cases you don't want to retrieve deleted records. Last year (somewhere in Aug or Sep) we had extensive discussion of this topic on UT. You coud search for that thread.
>>>
>
>Edward, I did try to find info under the search routine and got the following response:
>
>You have entered deleted. The result gives you a total of 1202 items found.
>
>The map and the message links are not available because you are not a Premier Universal Thread member.
>
>I am currently not a member but will be joining soon. Can you do me a favor for now?

One more UT tip: if email image is white, it's PUTM; if it's yellow, it's not PUTM. So, I am not.
Edward Pikman
Independent Consultant
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