Thursday, September 20, 2012 5:50 PM
We have a Datawarehouse using Oracle's ODI technology and Sql Server...... A consultant suggested we add the "query hint" (his words, not mine) /*+ PARALLEL */ to the sql query. Doing so improved execution speed by orders of magnitude but I can't find any t-sql references to it. Where is it documented?
Thursday, September 20, 2012 5:58 PMModeratorThat is an Oracle only optimizer hint; this does NOTHING in SQL Server -- except confuse people that read it. This particular optimizer hint is for a PARALLEL query. You might be able to find some information here. If you need more, I suggest that you ask your question in an Oracle forum.
- Edited by Kent WaldropMicrosoft Community Contributor, Moderator Thursday, September 20, 2012 6:01 PM
- Proposed As Answer by Samuel Lester - MSFTMicrosoft Employee, Moderator Thursday, September 20, 2012 6:22 PM
- Marked As Answer by Kalman TothMicrosoft Community Contributor, Moderator Wednesday, September 26, 2012 8:05 PM
Thursday, September 20, 2012 10:03 PM
As Kent points out, this is just white noise with no effect in SQL Server. If you saw a performance improvement, this could be because you changed the query text, and got a fresh compilation which fitted you current parameters better.
Erland Sommarskog, SQL Server MVP, email@example.com
- Marked As Answer by Kent WaldropMicrosoft Community Contributor, Moderator Wednesday, September 26, 2012 8:08 PM