Re: Can avoid list_copy in recomputeNamespacePath() conditionally? - Mailing list pgsql-hackers

amul sul <sulamul@gmail.com> writes:
> I wondered can we have a shortcut somewhat similar to following POC
> in recomputeNamespacePath () when the recomputed path is the same as the
> previous baseSearchPath/activeSearchPath :
> +   /* TODO: POC */
> +   if (equal(oidlist, baseSearchPath))
> +       return;

There's an awful lot missing from that sketch; all of the remaining
steps still need to be done:

        baseCreationNamespace = firstNS;
        baseTempCreationPending = temp_missing;

        /* Mark the path valid. */
        baseSearchPathValid = true;
        namespaceUser = roleid;

        /* And make it active. */
        activeSearchPath = baseSearchPath;
        activeCreationNamespace = baseCreationNamespace;
        activeTempCreationPending = baseTempCreationPending;

        /* Clean up. */
        pfree(rawname);
        list_free(namelist);
        list_free(oidlist);

More to the point, I think the onus would be on the patch submitter
to prove that the extra complexity had some measurable benefit.
I really doubt that it would, since the list_copy is surely trivial
compared to the catalog lookup work we had to do to compute the OID
list above here.

It'd likely be more useful to see if you could reduce the number of
places where we have to invalidate the path in the first place.