Re: Index performance

In article dated 14 Aug 1996 15:36:18 GMT, Glen Nunes (73044.1336_at_CompuServe.COM) wrote:
> We are having performance trouble with a batch process and we've
> narrowed it down to index performance.
>
> We have created a brand new tablespace on a new drive. Our
> testing indicates a 1000 record insert that takes 6 second
> non-indexed, takes 55 seconds or more when indexed in any of a
> variety of ways.

Each time a record is inserted, the indexes have to be updated. Therefore you are doing more IOs for each insert as compared to whn you had no indexes. Indexes are a tradeoff between query performance and update performance.

You might consider dropping the indexes, doing your batch stuff and then recreating the indexes after the batch stuff is complete.

--
 _--_|\  John Verhoeven (johnv_at_acix.DIALix.oz.au or johnv_at_DIALix.oz.au)
/      \ >>>> Writing programs in assembler is like digging post <<<<
*_.--._/ >>>> holes with a teaspoon:  it takes a long time, but  <<<<
      v  >>>> you have complete control over all the dirt.       <<<<