I recently read or listened to something Tara Kizer said about developers coming to her on timeouts or slow running queries, and the resolution was usually updating stats. I think she went on to say something about eventually she worked with developers to update their code, but I can't find the article or podcast (it was something to the extent of her talking about early in her career, IIRC).
Anyway, I am experiencing the same issue after recently switching to using Ola Hallengren's scripts for maintenance. I started with a new company and I am working on moving everything over from maintenance plans (weekly index rebuilds) to using Ola Hallengren's stored procs with jobs (still doing weekly index/stats maintenance unless there is a reason to do it more frequently). The specific code I am using for this is:
EXECUTE dbo.IndexOptimize @Databases = 'ALL_DATABASES', @FragmentationLow = NULL, @FragmentationMedium = 'INDEX_REORGANIZE,INDEX_REBUILD_ONLINE,INDEX_REBUILD_OFFLINE', @FragmentationHigh = 'INDEX_REBUILD_ONLINE,INDEX_REBUILD_OFFLINE', @FragmentationLevel1 = 5, @FragmentationLevel2 = 30, @UpdateStatistics = 'ALL', @OnlyModifiedStatistics = 'Y', @LogToTable = 'Y'
Oddly enough, after switching to this I am getting developers approaching me, exactly as Tara mentioned, and the fix for every single case has been updating stats (it has been 4 or 5 situations, and repeating periodically). Without discussing specifics of each case, any idea why this would surface all of sudden? Its too coincidental that I never saw any issues before, and it's only happened after switching to Ola's scripts. I am sure I could dig into each case and find bad code behind all of them, but holistically, what would be different about the two situations (MPs vs. Ola's scripts)? Maintenance plans are ugly, and I don't want to go back, but I am having a hard time expressing a business value for going to jobs with Ola's SPs, when we're having production issues since switching.
I appreciate any thoughts anyone has on this.