Hi Sofiane -
We rely on the JET (Microsoft Access) database engine to "talk" to CSV files for us, and the message you're seeing is coming from there.
Generally, JET reports this error when the question Tableau asks it is too complicated for it to process - not because of the size of the CSV file itself. Size still could be the problem, but I suggest you try and rule out the "too complex" bit first.
Have you added any new calculated fields or groups lately? If so, temporarily remove them from a copy of your workbook, try your extract again and see if it works. Calculated fields and Groups make for more complex queries.
Also, have you verified that a smaller version of the CSV file still does work?
Nothing new has been added. As soon as it hits 4GB I get this error message. If I make the csv smaller than 4GB extract works well.
Since CSV files are just text, why there's no native support in Tableau (without using Microsoft JET)?
JET is used against a number of file formats: CSV, Excel, and Access itself. Primarily, it used to figure out the data types of the underlying data source and parse complex queries. Tableau actually has it's own Text File Parser that can deal with files over 4 GB, but you need to make sure it gets invoked:
- The being executed must be "trivial" - no JOINs between CSV files, no custom SQL, no filtering
- Will only be used in Extract scenarios
- The target file can't contain fields which require JET for processing due to their complexity
All in all, you'll probably do best by getting in touch with Support to help you with this. Let them know that it seems JET is getting in the way, that you want to use Tableau's "TextFileParser" (no spaces) and they should be able to give you some direction.
I'm also happy to give this a look, but I'll need your data, and I suspect you can't just shoot it over.