Referring back to the previous page, here we shall now take a look at the log information, to help us understand how the VizQL engine is interpreting our calculations to SQL. From here, we can decide whether we can re-write the query to be more performant, or whether we can optimise the data source.
Data source optimisation really is limited to a database such as Microsoft SQL Server, Teradata, Oracle etc; though there might still be opportunities to speed-up flat-file too.
Remember, your data source(s) determine where Tableau logs the query information to, though as a minimum, you will need:
- For flat-files: hyperd.txt
- For database: the second tabprotosrv file created in sequence with the later time-stamp
Get a source code editor
Given their size, both in row count, but also row length, working with the logs is soo much more easier when opened in a source code editor rather than the Windows Notepad, just be sure that your editor can open and refresh actively in-use files.
Though there are plenty of free and proprietary source-code editors available, my favourite is Notepad++ which you can get from here, based on its size, minimal resource consumption, great feature list, language detection and support, and that it can be ran from a portable exe, so no install necessary