Functional ask - Choose column function re usability and its performance check.

[Anonymous]

Hi,

After establishing my connectivity to my data source, my query has returned for Example lets say : 25 Columns. 

Out of these 25 Columns, I would actually need 5 for now. So I use the Option Choose Columns and retrieve my only 5 columns that would suffice my requirement. 

After retrieve of choosing my 5 columns, I perform various function on my Edit query option. 

Lets say filtering my 5 Columns is step 5 and after that i had 5 more additional functions performed. (So in total there are 10 steps performed in Edit query)  (Please Refer the Mock Below for assumption)

Knowing that as days progress there is always scope for refinement in Data that might be required.

In This situation following are my questions. 

1. In Future, If i would need few more columns to be retrieved. Can I go back to Step 5 and underneath the option Choose Columns to just add more columns to the list without creating a newer step? (Its like adding my intended additional columns to my existing filter thats it) 

2. As mentioned on the very start. There are 25 columns that my data source returned as a response to my query. But in the end there are only 6-8 columns that can help me deliver my requirement. But When i refresh my reports does the query gets refreshed for all the 25 columns irrespective of the visuals i have in my report which is a result produced out of 6-8 columns? 

Thanks,

Govind

[Greg_Deckler · Accepted solution]

1. Yes

2. The query will retrieve the full table and perform operations on the on the full table up until step 5 when the other columns are dropped.

[luapdoniv]

My thoughts on your queries:

1. The chose cols introduces a step "Remove Cols". At any later point you can visit that step, and click on the cob wheel to edit and pick the required cols.

2. On the data refresh, to my understanding the modeling steps is what is traversed through for data load. So if you have removed 10 cols, those data won't populate and when you bring in new cols, those data will populate.