record from plpgsql function performance - Mailing list pgsql-general

Hello,

I have some simple function. The returned data set is generated based on view (dynamic - can be changed on daily basis). 

So the function was defined this way:

 1. returns setof some_view as ...

 2. inside the function I'm generating dynamic SQL into v_sql variable.

 3. return query execute v_sql

Everything works fine if I'm running single function, like:

select * from function (param1, param2)

I'm getting the delimited fields in desired order.

But if I want to run the function in inline mode, like:

select function(param1, param2) from some_table;

so the returned datatype is record.

To return multiple fields, I'm trying to use:

select (function(param1, param2)).* from some_table;

But this operation has a huge performance impact, IMHO runtime multiplied by number of columns - the function is executed for each column separately. 

In my case normal inline run is about 2 seconds for 300-400 records, but with ().* it's increased to 90-120 seconds.