Tom Lane wrote: > Hiroshi's "DROP_COLUMN_HACK" was essentially along this line, but > I think he made a representational mistake by trying to change the > attnums of dropped columns to be negative values.
Negative attnums had 2 advantages then. It had a big advantage that initdb isn't needed. Note that it was only a trial hack and there was no consensus on the way. It was very easy to change the implementation to use attisdropped. OTOH physical/logical attnums approach needed the change on pg_class, pg_attribute and so I've never had a chance to open the patch to public. It was also more sensitive about oversights of needed changes than the attisdropped flag approach. > That means that > a lot of low-level places *do* need to know about the dropped-column > convention, else they can't make any sense of tuple layouts. Why ? As you already mentioned, there were not that many places to be changed. Well what's changed since then ? regards, Hiroshi Inoue ---------------------------(end of broadcast)--------------------------- TIP 6: Have you searched our list archives? http://archives.postgresql.org
