In our company we don't use Service Now direct connection to Tableau but then we have copied the Snow data to a repository like Reporting Oracle DB since we encountered performance issues as you said, also it would compete with the transaction DB resources
Coming to your question "Extract. Live is greyed out." yes , please find below
Probably due to above reason only there is no Live connections allowed now (guess earlier it was)
After you select the sheet tab, Tableau imports the data by creating an extract. Note that Tableau Desktop supports only extracts for ServiceNow. You can update the data by refreshing the extract. For more information, see Extract Your Data.Creating extracts may take some time depending on the amount of data that is included.
The best way to connect Tableau to ServiceNow is to connect it to a mirrored database. It is not a good idea to connect live to ServiceNow because some complex queries might severely impair performance of the instance. The original ODBC driver is very limited as well.
We are very successful running Tableau against our own database with data downloaded via SnowMirror tool (www.snow-mirror.com). It's easy to use and you have your data in a real database such as Oracle or SQL Server.
Please read this post Connecting Tableau with Service Now
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Thanks very much for the quick and comprehensive response.
We have a reporting instance so we wouldn't be pulling from the Production\Live instance. We are refreshing it daily so in theory, that seemed like a good way to avoid transactions moving around at the same time. I just didn't anticipate there being such slowness.
I will talk with my DBA about extracting the data. I was hoping to avoid that all together with the Snow connection.