I am new to Tableau. I'm extracting tables from MS Access. In the process, I'm having to convert date fields from text to the data type Date. Each time I do this, I need to do a total refresh of the extracts in order for the conversion to take place. Each refresh is loading a billion+ records. Is there a more efficient way to do this?
You can try using a calculated field that will convert text to date and leave the original data as is, i.e. DATE([your_text_date]), instead of changing the data type of the field. This should not require extract refresh, but it depends on the details of your process.
How did you fit billion+ records in Access to begin with?