Preceding load

[#1]

Good morning-

I still seem to have some confusion about preceding load. I know conceptually that Qlikview reads bottom to top when a precedling load (or loads!) is in place.

Can someone help me understand this detailed point?

Sample Scenario - I have 3 million projects, each with a separate 5 digit project number

If I did a preceding load like the following:

Projects:

LOAD  ProjectNumber = '12345'     as ProjectNumber

          ProjectName

SQL Select

          ProjectNumber

          ProjectName

               FROM:OracleViews.

STORE Projects into "BLAHBLAH.QVD"

Would Qlikview pull ALL 3 million project numbers from my database views, THEN narrow it down to just my one project number? Obviously I'd be loading more than one project number, but I'm just trying to figure out the best way to limit the data I get ON AN INITIAL LOAD. QVD and incremental loads will help with this going forward.

During that initial load, I'm trying to limit the number of records it pulls to the ones relevant to my area. Where statements always seem to slow things down (there are some indexing challenges with how our initial database setup was done, that I have confirmed with someone I trust).

Any thoughts?

Thanks!

[#2]

And yes, I know 3 million with 5 digits doesn't add up. Just humor me.

[sunny_talwar · Accepted solution]

If you just want to see project number 12345, then you will need a where statement at the end, maybe like this

Projects:

LOAD  ProjectNumber

          ProjectName

SQL Select

          ProjectNumber

          ProjectName

FROM:OracleViews

Where ProjectNumber = 12345; (if 12345 is a number, else use '12345')

Update: Have never tried a where clause with Preceding load, but I believe it should work.

Best,

S

[#4]

Thanks! That's what I was afraid of. Because of some setup issues, where clauses tend to slow things down. But at least I know I'm on the right track. Thanks!

[sunny_talwar]

Yup no problem at all.

If you want to list a project you want to bring in, then I would probably use Where Exist (preferred, if the list is a long one) or Where Match (if list of projects you need to bring is short).

Best,

S

[#6]

Awesome - thanks for the extra tip!