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Count(*) vs exists on non indexed columns

vijzMay 8 2018 — edited May 8 2018

Apologies, for not providing table data

For a given  two non indexed tables (for some reason) with more than million records.

Which is the best option among the below to check if record exists:

A. Cost to execute query

B. Time to execute query

1.(Select Count(*) from tables where <condition> and rownum=1)>0

2.  Exists(Select null from tables where <condition>
This post has been answered by Sven W. on May 8 2018
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Locked on Jun 5 2018
Added on May 8 2018
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