At 11:42 AM 3/8/2006, Nilesh Patel wrote:
Dear Nilesh,

The fact that the Get was faster over chain has little to do with the 
$lookup, it is
based on the number of reads that have to be done.

All is explained in this article here.

http://www.robelle.com/newsletter/w1998-05.html#getchain

Again holding the first table and converting the other tasks to use
get vs chain may help as well as mentioned yesterday.

Neil


>Hi,
>
>I think that you could be right.
>
>The way we used the $LOOKUP was as follows:
>
>BASE base1,3
>SET STATISTICS ON
>SET DEFER ON
>
>TABLE one,key1,FILE,subf1
>GET set1
>IF $LOOKUP(one=key1)
>EXTRACT field1
>OUT set1out,LINK
>DELETE
>XEQ
>
>Once we changed it to CHAIN, we had an improvement on performance against
>the $LOOKUP. In fact, $Lookup is performing a selection, whereas Chain is
>doing a keyed read.
>
>Do you know how else I could have used $LOOKUP to improve the performance?
>
>Thanks.
>
>Nilesh.
>
>
>
>
>
>Internet
>[log in to unmask]@RAVEN.UTC.EDU - 07/03/2006 19:53
>
>Please respond to [log in to unmask]
>Sent by:        [log in to unmask]
>To:     HP3000-L
>cc:
>Subject:        Re: [HP3000-L] Help with suprtool
>
>
>the $LOOKUP function will likely speed things up a great deal
>
>Regards,
>
>Judythe La Londe
>
>
>Nilesh Patel <[log in to unmask]> wrote:
>Hi,
>
>Is there a way to improve the following suprtool code:
>
>BASE base1,3
>SET STATISTICS ON
>SET DEFER ON
>
>TABLE one,key1,FILE,subf1
>CHAIN set1,key1=one
>EXTRACT field1
>OUT set1out,LINK
>DELETE
>XEQ
>
>TABLE two,field1,FILE,set1out
>CHAIN set2,field1=two
>DELETE
>OUTPUT $NULL
>XEQ
>
>TABLE three,key1,FILE,subf1
>CHAIN set3,key1=three
>DELETE
>OUTPUT $NULL
>XEQ
>
>
>The SUBF1 file is a subfile created by a QTP with the parent details.
>
>Thanks in advance.
>
>Nilesh Patel.
>
>
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