2010/1/28 Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>:
> Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com> writes:
>> in 99.99% the second argument will be a constant. Can we use this
>> information and optimize function for this case?
>> The detoast on every row can take some percent from a performance.
> What detoast? There won't be one for a constant, nor even for a
> variable in any sane situation --- who's going to be using
> multi-kilobyte delimiter values? And if they do, aren't they likely
> to run out of memory for the result long before the repeated detoasts
> become an interesting problem? You're arguing about a case that
> seems quite irrelevant to the real world.
with get_fn_expr_arg_stable() we are able to fix second parameter
without some performance issues.
> regards, tom lane
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