Re: Possible micro-optimization in CacheInvalidateHeapTuple

Jim Nasby <Jim.Nasby@BlueTreble.com> writes:
> CacheInvalidateHeapTuple currently does the following tests first; would there be a performance improvement to
testingthe system relation case first? We're almost never in bootstrap mode, so that test is almost always a waste. Is
thereany reason not to switch the two?
 
>     /* Do nothing during bootstrap */
>     if (IsBootstrapProcessingMode())
>         return;

>     /*
>      * We only need to worry about invalidation for tuples that are in system
>      * relations; user-relation tuples are never in catcaches and can't affect
>      * the relcache either.
>      */
>     if (!IsSystemRelation(relation))
>         return;

You're assuming that IsSystemRelation() is safe to apply during bootstrap
mode.  Even if it is, I don't see the point of messing with this.
IsBootstrapProcessingMode() is a macro expanding to one comparison
instruction.
        regards, tom lane