Tom Lane wrote: > Allan Tong <[EMAIL PROTECTED]> writes: > > I'm not sure if this is the right list to send this, but any help > > would be appreciated. We recently encountered a problem running > > postgres where, after a vacuum, all the data in one of our tables > > was gone. Now, I guess technically we don't know for sure if it > > was indeed vacuum that caused the data loss, but it seems likely. > > The vacuum output shows that it thought it was removing only 27 out > of the nearly 700K rows. So I don't think vacuum is directly to > blame. However, it would very possibly have rewritten many of the > pages in your table, as a byproduct of moving rows, updating tuple > commit bits, etc. > > > ... when I looked at the file contents, it was almost > > completely null'ed, so it looks like the data is really gone (though > > shouldn't a full vacuum reclaim the space?). > > You mean the pages were all-zero? It sounds to me like a serious > hardware failure, or possibly kernel/filesystem misfeasance. Postgres > would certainly not have written zeroes, but apparently what got dropped > onto the disk platter was zeroes. Such failures are uncommon, but > by no means un-heard-of.
Isn't that what IDE gives you when it maps a new block to replace a corrupted one? -- Bruce Momjian | http://candle.pha.pa.us [EMAIL PROTECTED] | (610) 359-1001 + If your life is a hard drive, | 13 Roberts Road + Christ can be your backup. | Newtown Square, Pennsylvania 19073 ---------------------------(end of broadcast)--------------------------- TIP 8: explain analyze is your friend
