Do not input private or sensitive data. View Qlik Privacy & Cookie Policy.
Skip to main content

Announcements
Want to see what's currently in public preview? We've pulled it all together in one place. Check it out here
cancel
Showing results for 
Search instead for 
Did you mean: 
Not applicable

'Where' Performance reading from QVD;

Hello All!

Need some advice on the best way to approach this,

I'm trying to load data from a (Optimised) QVD,

I have around 15-16 individual load statements with separate 'Where' clauses, all concatenated together.

As the load times are significantly slower than i expected - please can anyone offer any advice on how to improve performance.

Example

Controls:

LOAD

'Opp' as [Type],

id,

Date

FROM Ticket.QVD (Qvd)

WHERE

[Task 1 Due] <= $(vToday);

Concatenate

LOAD

'Achieved' as [Type],

id,

Date

FROM Ticket.QVD (Qvd)

WHERE

[Task 1 Due] <= $(vToday) AND

[Task 1 Due] >= [Task 1 Done];

....................





Labels (1)
3 Replies
vincent_ardiet
Specialist
Specialist

Hi,

Have you try to use a resident table ?

First load Ticket.QVD with no filter then perform several resident load.

Regards,

Vincent

Not applicable
Author

Hey,

Yes, i have tried but as we have a very large data set, holding that much data in memory (resident) also was having difficulties.

Thanks

vincent_ardiet
Specialist
Specialist

Ouch !

And if you try to mutualize some loading, for example something like :

Controls:

LOAD

'Opp' as [Type],

id,

Date,

[Task 1 Due],

[Task 1 Done]

FROM Ticket.QVD (Qvd)

WHERE

[Task 1 Due] <= $(vToday);

Concatenate

LOAD

'Achieved' as [Type],

id,

Date,

[Task 1 Due],

[Task 1 Done]

RESIDENT Controls

WHERE

[Task 1 Due] <= $(vToday) AND

[Task 1 Due] >= [Task 1 Done];

Then you can drop the unused columns.

Regards,

Vincent