Years ago, it was common to write
where exists (Select * from some_table where some_condition)
Last year I noticed that many t-sql scripts switched to using the number 1 instead of the star
where exists (Select 1 from some_table where some_condition)
just on SO I saw this Oracle example
WHERE EXISTS (SELECT NULL FROM ...
Is this a common pattern with Oracle? And which are the performance arguments to use something like this.