Re: patch: tsearch - some memory diet

Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com> writes:
> A more general solution would be to have a new MemoryContext
> implementation that does the same your patch does. Ie. instead of
> tracking each allocation, just allocate a big chunk, and have palloc()
> return the next n free bytes from it, like a stack. pfree() would
> obviously not work, but wholesale MemoryContextDelete of the whole
> memory context would.

The trick with that is to not crash horribly if pfree or
GetMemoryChunkSpace or GetMemoryChunkContext is applied to such a chunk.
Perhaps we can live without that requirement, but it greatly limits the
safe usage of such a context type.

In the particular case here, the dictionary structures could probably
safely use such a context type, but I'm not sure it's worth bothering
if the long-term plan is to implement a precompiler. There would be
no need for this after the precompiled representation is installed,
because that'd just be one big hunk of memory anyway.

regards, tom lane