Re: why provide cross type arithmetic operators

"ykhuang" <hyk(at)ruc(dot)edu(dot)cn> writes:

> there are many cross type arithmetic operators, like int2 + int4, int8 +
> int4, I think these can be deleted. Here are the reasons, after deleted,
> int2 + int4 will choose the operator int4 + int4, int8 + int4 choose int8 +
> int8, Is that ok? Thanks.

Then the system wouldn't be able to use indexes as flexibly. For example if
you have an index on an int2 column and perform a query with a restriction
like "int2col = 1" the system wouldn't find a matching =(int2,int4) operator
and would instead have to do a sequential scan casting the int2 column to an
int4 when checking each row.

--
Gregory Stark
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