Dear Community,

I am trying to make a union of 300+ csv files. (each file at size from a few kb to ard 100mb, totaling ard 3 GB)

I got error messages:

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"An error occurred while communicating with the data source.

Bad Connection: Tableau could not connect to the data source.

ERROR:  unexpected end-of-file in file:'stdin' "

when I press the "Update Now" button in the Data Source tab of Tableau.

&

"Bad Connection: Tableau could not connect to the data source.

ERROR: unexpected end-of-file in file:'stdin'

Unable to properly calculate the domain for the field 'Fare Position (Inbound XXX)'. Displayed data may be incorrect."

( 'Fare position (Inbound XXX)' is a self-created calculated field)

When I press any other tab of the workbook (which are 3 worksheets and 1 dashboard)  

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I tried to troubleshot the matter by union a few number (2-20) of the files manually, sometimes it works for some union sequences but not others and sometimes the same error messages pop up.

Would like to ask the community if there is a better a way to solve this?
I cannot combine all the csv files manually into 1 csv file as it will exceed the excel row limit (ard 1 million row).

Million thanks for the help