inlist iterator algorithm

From: Dba DBA <oracledbaquestions_at_gmail.com>
Date: Wed, 6 Jul 2011 15:46:56 -0400
Message-ID: <CAE-dsOKkcokGkGq=pPRLHGmBYJA9tYug+2S7VKCi22S8T9CJEw_at_mail.gmail.com>

I am not sure if this is documented. I am just curious.

When Oracle does an inlist iterator, what is it doing under the cover. When I think "iterator", I think

   for i in array.start.. array.end

      run query(i)
   end loop;

so if i have 5 values in the inlist, the query runs 5 times. once for each value in the inlist.

My understanding
1. In, is a group of "or" statements
2. Or is the samething as a union all

So when you do an or or a union all, you are running 2 queries.

Is the inlist smarter than that?

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Received on Wed Jul 06 2011 - 14:46:56 CDT