Is it better to join in the sql statement or in qv ?

[#1]

Hello everyone,

Which solution is better for general performance ?

1)

A:

LOAD

id1,

id;

SELECT

id1,

id

FROM TABLEA;

LEFT JOIN (A)

LOAD

id

lala;

SELECT

id, lala

FROM TABLEB;

2)

LOAD

id1, lala;

SELECT

id1, lala

FROM TABLEA LEFT JOIN TABLEB on TABLEA.id=TABLEB=id;

?

Thank you for your answer

Have a good day

Laura

[#2 · Accepted solution]

It is usually better to do it on QV. This way you will not impact the performance of the SQL server.

Instead of using joins try using Mapping Load and ApplyMap(). It is way faster than doing joins and for your example it works perfectly:

Don't join - use Applymap instead

[#3]

I would use sql join instead of QV if the tables are huge, it would give better performance. It all depends on the table sizes