topic Re: summarize vs addcolumn in DAX Commands and Tips

summarize vs addcolumn

Anonymous — Tue, 17 Sep 2019 14:28:47 GMT

Hello,
The following two queries give the same result.
Which is the best to use and why?
I feel like summarize is simpler for me to use.

Thank you

ADDCOLUMNS (
GROUPBY (
'TableX'
,'TableO'[field1]
,'tableY'[field3]
)
,
"duration", 'TableX'[field5]
)

////////////////////////////////////

SUMMARIZE(
'TableX'
,'TableO'[field1]
,'tableY'[field3]
, "duration", 'TableX'[field5]

Re: summarize vs addcolumn

Nathaniel_C — Tue, 17 Sep 2019 20:26:02 GMT

Hi Anonymous ,

Here is a good blog by marcorusso who is the guy to ask!

His conclusion is below. There are a ton of books and blogs to answser other questions like this.

If this solves your issues, please mark it as the solution, so that others can find it easily. Kudos are nice too.
Nathaniel

The conclusion is that extended columns in a SUMMARIZE expression should not be moved out to an ADDCOLUMNS if the table used in SUMMARIZE has particular filters and the extended column expression uses columns that are not part of the output. Even though you can create an equivalent ADDCOLUMNS query, the result is much more complex and there are no performance benefits in this refactoring. The more complex query has the exact same (not so good) performance as the SUMMARIZE query – both queries in this section require almost 20 seconds to run on Adventure Works 2012 Tabular.

Re: summarize vs addcolumn

marcorusso — Wed, 18 Sep 2019 00:59:06 GMT

In reality this would the the best one:

SUMMARIZECOLUMNS (
    TableO[field1],
    tableY'[field3],
    "duration", [field5]
)

And if you cannot use SUMMARIZECOLUMNS then:

ADDCOLUMNS (
    SUMMARIZE (
        TableX,
        TableO[field1],
        tableY[field3]
    ),
    "duration", [field5]
)