HTDELETE Wait Type

Joey D’Antoni troubleshoots a query with excessive HTDELETE waits:

Ultimately I think any thought of the readable secondary having a vastly different plan was a red herrings. Statistics are going to be the same on both instances, and if there were a missing statistic on the secondary, SQL Server would create it in TempDB. Anyway, columnstore indexes don’t use statistics in the traditional sense.

Fortunately I was able to catch a query in the process of waiting on HTDELETE, so I no longer had to look for the needle in the haystack, and I could get to tuning the plans. I was able to grab the SELECT part of the query and generate an estimated plan on both the primary and secondary nodes. The plans were virtually the same on both nodes, with just a minor difference in memory grant between them.

Click through for the solution.

Related Posts

Linked Servers And Columnstore

Niko Neugebauer continues his columnstore series by looking at how they interact with linked servers: Lets us make sure everything is fine for data transfer and as we are using our source server (SQL Server 2014) with Linked Server to SQL Server 2016, let us insert a couple of ObjectIds to the T1 table that we have […]

Read More

Resumable Online Index Rebuild

Arun Sirpal shows off a SQL Server 2017 and Azure SQL Database feature: Clearly I am in a paused state with 5.48% percent of the operation complete. In the original query window where I started the index rebuild, I receive: Msg 1219, Level 16, State 1, Line 4 Your session has been disconnected because of […]

Read More

Categories

February 2017
MTWTFSS
« Jan Mar »
 12345
6789101112
13141516171819
20212223242526
2728