topic Re: Inner Keep, vs Exists - which is quicker in QlikView

Inner Keep, vs Exists - which is quicker

Fri, 26 Oct 2012 10:32:11 GMT

I have a fairly large fact table of 125m records.

In your opinion would it be quicker to use Inner Keep to reduce the fact table or the Exists() function?

Thanks!

Re: Inner Keep, vs Exists - which is quicker

perumal_41 — Fri, 26 Oct 2012 11:03:08 GMT

Exists function reloading time filtering data

inner keep function reload finished after filter data in memory.

so better use exists function useful for u

Re: Inner Keep, vs Exists - which is quicker

Fri, 26 Oct 2012 11:05:14 GMT

thanks.

Would appreciate other peoples views as well....

Re: Inner Keep, vs Exists - which is quicker

hic — Fri, 26 Oct 2012 14:22:35 GMT

I would say that inner keep is much faster than "Where Exists()". The exists() function makes a lookup for each record (which takes time for large tables) whereas inner keep compares two binary vectors after the load.

The exists() however has the advantage that it is easier to understand when you read the script a year later and have forgotten what you did...

I suggest you try both and see for yourself.

HIC