Hi all
I have a DMV which looks at the index information on my production server. In this view, I have around 3 weeks worth of data concerning the number of seeks, lookups, scans and updates each index has been used for. After slowly weeding out all the indexes that have no seeks and used mostly for scans, I am now in a position to delete and/or tune the rest of the indexes on the system. I have various scenarios present and was wondering if anyone could give me any advice on what to do with the following indexes?
- Seek count low, scan/lookup count = 0 and update count high (low R/W Ratio). I'm assuming I keep these sort of indexes due to seeks being used mostly (albeit rarely)
- Seek count low, scan count low, update count high (low R/W Ratio). My assumption is that I try to amalgamate this type of index into another existing one? Is there another solution to this type of index?
- Seek count low, scan count high/v high, update count med/high. Do I attempt to amalgamate this, leave alone or delete?
- Seek and Scan count equal, update count high and/or low. Leave these alone or look to amalgamate (due to higher level of scans)?
- Seek count high, scan count low, update count high/med/low. Definitely leave these alone.
With the above in mind, are there any tips on what I do for each scenario? Also, with regard to joining up indexes from others that may exist on any table, shall I use the missing indexes view or Profiler/trace?
Any other advice?
Thanks in advance.