Re: Writing triggers in C++

Florian G. Pflug wrote:
> Andreas Pflug wrote:
> >Tom Lane wrote:
> >>Jacob Rief <jacob(dot)rief(at)gmx(dot)at> writes:
> >>
> >>>I tried to write a trigger using C++.
> >>>
> >>That is most likely not going to work anyway, because the backend
> >>operating environment is C not C++. If you dumb it down enough
> >>--- no exceptions, no RTTI, no use of C++ library --- then it might
> >>work,
> >I can confirm that it does work this way.
>
> I've written an aggregate function that uses c++ stl hashes, and it
> seems to work pretty well. I'd think that using exceptions should be
> fine, as long as you make sure to _always_ catch any exception that
> might be thrown inside your own c++ code, and don't let it propagate
> into backend code. STL allows you to specify custom allocator classes
> as template parameters to hash, vector and the like. You can use that
> to let STL allocate memory from the correct memory context.

What happens if Postgres raises an elog(ERROR) in the code you're
catching exceptions in? Is it propagated outwards?

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Alvaro Herrera http://www.CommandPrompt.com/
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