Re: [Firebird-devel] UDR vs PSQL

[Leyne, S. <Se...@Br...>]

> Calling UDF is hard process. We must emulate C call stack therefore parameters
> are multiple times copied here and there, making CSTRING from CHAR /
> VARCHAR is also headache - there is no place for terminating zero in the end of
> that string, therefore memory allocation takes place.
> Almost all of that migth be avoided calling BY DESCRIPTOR but looks like there are
> not too much UDF doing this.

That would be incorrect.  A significant number of our UDFs pass parameters by descriptor.

What is the use case for them not to be handled that way?

As I understood it, passing by descriptor makes the call much faster (for the reasons you outline), no?


Sean