sql - PostgreSQL reusing computation result in select query -

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for example using sql can do:

select (a+b) c table c < 5 , (c*c+t) > 100;

is there way using postgres?

this alternative might use:

select foo.c (     select (a+b) c table ) foo foo.c < 5  , (foo.c*foo.c+t) > 100

from performance point of view, think it's not optimal solution (because of lack of clause of foo subquery, hence returning table records). don't know if postgresql query optimization there.


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