Rule of thumb! Thanks for the response Greg. Does this apply to Data warehouse or OLTP applications or both? On Thu, Aug 11, 2011 at 7:03 PM, Greg Rahn <greg@xxxxxxxxxxxxxxxxxx> wrote: > Sounds like the "index death spiral" to me. > My simple sanity check: when the total number of columns indexed is > greater than the number of columns in the table, there is likely a design or > tuning problem. Often times, even before then... > > > On Thu, Aug 11, 2011 at 1:45 PM, Ram Raman <veeeraman@xxxxxxxxx> wrote: > >> Listers, >> >> I am looking at a table in our system and it has 12 indexes, we are >> planning on adding another one. I am aware of the effects of having too many >> indexes, but in this case adding an extra index helps a certain query that >> runs slow. Other queries and most other operations against the table >> are acceptable too. I see a few tables like this; is there a number above >> which is considered a no-no when it comes to adding more indexes. >> >> PS. The tables and queries are structured in a way that seem to require >> several indexes - it is a third party product. >> >> TIA, >> Ram. >> > > > -- > Regards, > Greg Rahn > http://structureddata.org >