Incremental load with Composite key

[prabhu0505]

Hi All,

I want to implement incremental load with composite key, pls. give me suggestions.

Composite Key : Fields A, B, C, D make up the key. Here C is date Field.

Logic: Only Insert and Update. No Delete.

Thanks..

[mdmukramali]

Dear,

Please can you attach some sample data.

Thanks,

Mukram

[prabhu0505]

A	B	C	D	E	F
a1	b1	1/1/2014	d1	10	25
a1	b1	1/2/2014	d1	10	15
a1	b1	1/3/2014	d1	20	30
a1	b1	1/3/2014	d11	30	35
a2	b2	1/1/2014	d2	40	45
a2	b21	1/1/2014	d2	20	55
a21	b2	1/1/2014	d2	15	65

[maxgro]

you can find some help in online help

see attachment

[prabhu0505]

Hi Massimo,

I've currently 1 million record in the table expecting it to grow till 2 million within a year. So using string concatenation (A&'-'&B&'..)  will degrade the performance? Any other alternatives?

Thanks..

[maxgro · Accepted solution]

- autonumberhash... instead of concat (some goods readings on qlikviewnotes and qlikfix)

- store the primarykey calculated field in the qvd: you don't need to recalculate it every run

- some millions of records? don't  think they are a big number; but you can try to simulate the performance before

[prabhu0505]

My doubt is whether Autonumberhash will generate same key based on the combination of column.

Autonumberhash('a1','b1','01/01/2014',d1) will be same every time.

[maxgro]

- hash is hash, collision is possible, perhaps someone of Qliktech can clarify that

- if you want to store the primary key in qvd I think you should use hash (128 or 256) instead of autonumberhash