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Doharaquax's avatar
Doharaquax
Frequent Visitor
3 years ago
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Power query merge vs SQL joins

Hi,   Is it better to use Merge queries in power query if I need to merge columns into the final table or is it better to use SQL queries and join them this way. I'm using ODBC and learned how to u...
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  • edhans's avatar
    edhans
    3 years ago

    If connecting directly to SQL Server it may not matter as a merge in Power Query gets folded back to the server so the server does the join and merge. But if you are going through an ODBC driver, or using a data source that doesn't fold, then you definitely want to do the merge in the source database.

    The general rule is push tranformations back as far to the source as possible, but do them as late as is necessary. So if you have the option to do the merge in SQL and present a view to Power Query, do it.

edhans's avatar
edhans
Community Champion
3 years ago

If connecting directly to SQL Server it may not matter as a merge in Power Query gets folded back to the server so the server does the join and merge. But if you are going through an ODBC driver, or using a data source that doesn't fold, then you definitely want to do the merge in the source database.

The general rule is push tranformations back as far to the source as possible, but do them as late as is necessary. So if you have the option to do the merge in SQL and present a view to Power Query, do it.