Huge data transfer query

[finglem]

Hi folks I wonder if anone can help us with something.


I have a table with 86216 records 202 fields and it is 397meg in size.
If I query the table and select just one numeric 8 byte field and 3000 of those records over the network into a cursor it appears to be transfering over 17 meg of data across the network.
The field is indexed and the query has a nofilter statement
and I just cannot believe that it is bringing 17 meg across.
Has anybody any idea how this could be happening?

Any help on this would be appreciated

 

[pthalacker]

Does the query bring 17 meg across the second time it is run or only the first?

pamela

 

[finglem]

Hi Pamela thanks for responding

It only brings it across the first time it is run but 17 megs has got to be far too much for one little query surely

 

[TamarGranor]

Have you used SYS(3054) to see how VFP is optimizing with the query? That might give you some clues.

Tamar

 

[finglem]

Thanks Guys

The maths suggests that it does appear to returning all the fields regardless.
I'll have to have another look at what it is we really need to be doing.
Thanks again

 

[Mike Lewis]

Finglem,

Are you sure your query exactly matches your indexes? If the index is such that the query can't be optimised, you could find that, at best, you are transferring the contents of the field being queried from every record. And, at worst, the entire table.

Mike


__________________________________
Mike Lewis (Edinburgh, Scotland)

My Visual FoxPro site: www.ml-consult.co.uk