I have a client that used Itzik Ben-Gan’s solution of creating a filtered nonclustered columnstore index to achieve batch mode on a rowstore (in fact I proposed that the client consider it). They have an OLTP system, and often perform YTD calculations. When they tested, processing time was reduced by 30 to 50 percent, without touching a single line of application code. If that ain’t low hanging fruit, I don’t know what is —
However, during testing, I noticed some intermittent blocking that didn’t make sense to me. But I couldn’t nail it down, and they went live with the “filtered nonclustered columnstore index” solution.
Once they deployed – and there was a lot of concurrency – I could see what had eluded me during my proof of concept: blocking in tempdb.
Read on for the repro and check out Ned’s UserVoice bug report.