Good Indexes Make Good Queries

Thomas Rushton has an example of a positive indexing experience:

100k runs of the query in a ten minute interval? yeowch. Yeah, this should be optimised if possible. The primary wait type was CPU – indicating that the data was all in RAM, but the CPU was having to schlep through the entire table to find what it needed. Or to find that it didn’t need anything. Or something.

The interesting story buried in here is that none of the tooling Thomas used indicated that things could be improved with a better index, and yet there was a tremendous opportunity here based on the graphics at the end.

Related Posts

Index Changes And Recompilation

Kendra Little explains how index modifications affect the plan cache: Creating an index doesn’t remove a plan from cache We run our Demo Query five times. Querying sys.dm_exec_query_stats and related DMVs, we see five executions, plan_generation_num = one. Then we create an index on a table referenced by the query. Querying the DMVs we still see […]

Read More

Deletes And Indexes

Jeff Schwartz looks at the performance cost of indexes when it comes to deleting rows: Many articles concerning SQL Server discuss how record insertion overhead increases with each additional index. They discuss b-tree manipulations and page splits in addition to leaf and non-leaf levels. However, few discuss the fact that deletion overhead increases as well, […]

Read More

Categories

June 2017
MTWTFSS
« May Jul »
 1234
567891011
12131415161718
19202122232425
2627282930