> > And, while we are on heap subject - using index (RECNO) for heap
> > means that all our secondary-index scans will performe TWO
> > index scans - first, to find recno in secondary-index, and
> > second, to find heap tuple using recno (now indices give us
> > TID, which is physical address).
>
> Yes, that was one of my questions. Why use recno at all? We already
> have heap access which is very fast. Why switch to SDB which gives us
> a recno ordering of heap that doesn't do us any real good, except to
> allow tuple update without changing indexes.
But if we'll use our heap AM, then we'll have to implement redo/undo
for it... no sence to switch to SDB for btree/hash WAL support -:)
Vadim