Merge or Append 2 big table's columns

[Anonymous]

Dear  all,

I have 2 big tables(For example Table A and Table B), which contains many columns and no of records(more than 65,00,000 records) also more.

Now i want to merge/Append Table B's 5 columns with Table A. I tried with Merge/Append option in Power BI editor. But it took more time and sometimes the Power BI got crashed.

Is there any better way to Join/Append/Merge only selected columns from Different table(For example From Table B to Table A) without any delay or crash in Power BIU desktop.

And let me know what is the exact use of "LOOKUPVALUE" API. Will it be helpful to merge/Append desired columns from Table B to Table A(For example).

Thanks & regards,

Pon maheswaran K

[amitchandak]

@Anonymous , refer these two can help

Power query
https://radacad.com/append-vs-merge-in-power-bi-and-power-query

DAX
https://www.sqlbi.com/articles/from-sql-to-dax-joining-tables/

[Greg_Deckler]

LOOKUPVALUE is a DAX function and generally not related to merging or appending tables in Power Query, which uses M and not DAX. LOOKUPVALUE is generally used to lookup values in unrelated tables.

As for the rest of it, there is simply not enough information to go on.

[Anonymous]

Dear @Greg_Deckler & @amitchandak  ,

Thanks for your reply on LOOKUPVALUE and URL.

i have Table A and Table B. Both are very big tables and contains more than 6500000 records.

Between Table A and Table B, "EmpId" and "Date" are common columns exists in both the tables.

And i need to merge/Append only 2 columns from table B to Table A. Is there any easy approach to acheive this?

Please let me know.

Thanks Regards,

Pon maheswaran K

[Greg_Deckler]

I believe the most efficient approach would be to create a combination key from those two columns in each table. Create a bridge table of unique values. Form the relationships. Relationships will be orders of magnitude faster than LOOKUPVALUE or even, likely, merge operations.

[amitchandak · Accepted solution]

@Anonymous , you can move like

New column in Table A = maxx(filter(TableB, TableB[empid] =TableA[empid] && TableB[Date] =TableA[Date]),TableB[Col1])

Change join and Aggregation as per need. This is a costly operation. See if you can work with common dimensions and measures