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Should I add DELETED() tag
Message
 
 
À
15/05/2001 09:41:10
Information générale
Forum:
Visual FoxPro
Catégorie:
Base de données, Tables, Vues, Index et syntaxe SQL
Divers
Thread ID:
00507170
Message ID:
00507245
Vues:
28
Hi!

2 indexes - larger CDX - more data to transfer through network - slower application.

What is benefit for adding deleted() filter to the primary key tag? Once I tried to gendbc.prg such database made by other developer. After making PRG I discovered that I had to make filters manually because there are no way to do this for primary key tags programmatically (you can read this in the comments inside of the gendbc tool). So, why messing with it?

I remember, this was already discussed somewhere at the http://fox.wikis.com site.

>SNIP
>>
>>You should avoid filters in other indexes. I know there are people that recommend to filter indexe by deleted(), however, this is completely wrong because such indexes are not used in the optimization. Just the deleted() as an index expression is fine.
>>
>SNIP
>
>Hi Vlad,
>
>It is not "completely" wrong - any time that I have seen that advice it was also accompanied by a recommendation to *ALSO* make another TAG on the same expression *without* the filter.
>And the filter was virtually always suggested for the PRIMARY key or a CANDIDATE key. That is, not willy-nilly for many TAGs.
>
>Cheers,
>
>JimN
Vlad Grynchyshyn, Project Manager, MCP
vgryn@yahoo.com
ICQ #10709245
The professional level of programmer could be determined by level of stupidity of his/her bugs

It is not appropriate to say that question is "foolish". There could be only foolish answers. Everybody passed period of time when knows nothing about something.
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