Hiroshi Inoue wrote: > Bruce Momjian wrote: > > > > Hiroshi Inoue wrote: > > > > Makes sense. Of course, we could make a syscache that didn't return > > > > system columns either. > > > > > > > > Actually, the original argument for negative attno's for dropped columns > > > > was exactly for this case, that the system column check would catch > > > > dropped columns too, > > > > > > > but it causes other problems that are harder to fix > > > > so we _dropped_ the idea. > > > > > > What does this mean ? > > > > Client programmers prefered the dropped flag rather than negative > > attno's so we went with that. > > What I asked you is what *harder to fix* means.
Uh, some said that having attno's like 1,2,3,5,7,8,9 with gaps would cause coding problems in client applications, and that was easier to have the numbers as 1-9 and check a flag if the column is dropped. Why that is easier than having gaps, I don't understand. I voted for the gaps (with negative attno's) but client coders liked the flag, so we went with that. > > > BTW would we do nothing for clients after all ? > > > > Clients will now need to check that dropped flag. > > Clients would have to check the flag everywhere > pg_attribute appears. > Why should clients do such a thing ? Well, good question. They could easily skip the dropped columns if we used negative attno's because they usually already skip system columns. However, they prefered a specific dropped column flag and positive attno's. I don't know why. They would have to explain. >From my perspective, when client coders like Dave Page and others say they would prefer the flag to the negative attno's, I don't have to understand. I just take their word for it. -- Bruce Momjian | http://candle.pha.pa.us [EMAIL PROTECTED] | (610) 853-3000 + If your life is a hard drive, | 830 Blythe Avenue + Christ can be your backup. | Drexel Hill, Pennsylvania 19026 ---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/users-lounge/docs/faq.html
