topic Re: Keep keyword in QlikView

Keep keyword

Wed, 25 Nov 2020 16:16:04 GMT

Hi Team,

Would anyone can tell me the purpose/use of keep keyword. I read it you can use it JOIN/KEEP keyword where join will join and will show 1 table, KEEP keyword keeps 2 tables. my question is that why we would need KEEP keyword in real time?

Thanks.

Re: Keep keyword

avinashelite — Mon, 30 Jan 2017 08:55:48 GMT

If you have table 1 with 10 columns and 10K records and table 2 with 4 columns and 20 records.

In this case if you join the table2 with table1 then it will generate 10K records for the 3 columns in the table1 which is not feasible intend of that Keep just reduce the data in the table 2 in accordance with table 1 without joining and creating additional records

Hope this helps you

Re: Keep keyword

tresB — Mon, 30 Jan 2017 08:56:58 GMT

This has been discussed here: Re: KEEP command - why to use that?

Re: Keep keyword

vinieme12 — Mon, 30 Jan 2017 09:40:31 GMT

read this thread

Understanding Join, Keep and Concatenate

Re: Keep keyword

sdmech81 — Mon, 30 Jan 2017 09:44:18 GMT

There are many advantages of keep compared to join but it depends on the scenario:

It will avoid one to many relation wrong calculations,check here when to use Join and when to use Keep ?

its use can also reduce the table size.

Take scenario where u have master calendar with future date and there is one main data table.Its not recommended to join data with calendar, though you can associate but using Keep will also solve the purpose and also reduce the data size by comparing dates in main table.

hope it helps.

Sachin

Re: Keep keyword

jonathandienst — Mon, 30 Jan 2017 09:55:06 GMT

One scenario that I commonly use is to reduce dimensions so that only the relevant dimension values get loaded 0 like this:

Transactions:

LOAD TransID,

TypeCode,

...

Left Keep(Transactions)

TypeCodes:

LOAD TypeCode,

TypeDescription,

TypeCategory,

...

But one could also use this for the same result:

Transactions:

LOAD TransID,

TypeCode,

...

TypeCodes:

LOAD TypeCode,

TypeDescription,

TypeCategory,

...

WHERE Exists(TypeCode)