Re: Index help

Data distribution.
 
IDA3A5     count(IDA3A5)
4104                           44
4107                         156
4110                             1
4111                             1
4137                             1
46847                      4905
Daniel Fink <Daniel.Fink@xxxxxxx> wrote:
Assuming a uniform distribution, an index would probably make sense. If the 
data is skewed (1 value is in 80% of the rows, etc.), an 
index may not make sense. If the CBO uses bind peeking at parse time, you could 
end up with a poor execution plan. For example, the 
first call uses the 80% value in the predicate, so Oracle decides to use a FTS. 
Subsequent executions use the other values or even a 
value that does not exist. These executions are also going to use an FTS, when 
an index lookup is probably faster.

Daniel

M.Godlewski wrote:
> 6 distinct values for ida3a5

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