Обсуждение: Vacuum error on database postgres
I'm running postgreSQL 8.1.4 on Red Hat Enterprise Linux 3. Things have been working well for a while but in the last few days, I've gotten the following error during a nightly vacuum. postgres=# vacuum analyze; ERROR: duplicate key violates unique constraint "pg_statistic_relid_att_index" I can vacuum that table individually without problems. postgres=# vacuum pg_statistic; VACUUM postgres=# vacuum analyze pg_statistic; VACUUM postgres=# I found a posting from 2004 that suggested the following query. postgres=# select starelid, staattnum, count(*) from pg_statistic group by 1,2 having count(*) > 1; starelid | staattnum | count ----------+-----------+------- 2608 | 3 | 2 10723 | 7 | 2 10723 | 4 | 2 10723 | 5 | 2 10723 | 2 | 2 10723 | 3 | 2 10728 | 1 | 2 10728 | 2 | 2 10728 | 3 | 2 10728 | 4 | 2 10728 | 5 | 2 10738 | 1 | 2 (12 rows) I did delete exactly one of each of these using ctid and the query then shows no duplicates. But, the problem comes right back in the next database-wide vacuum. I think the objects are as given below. postgres=# select relname,oid,reltype from pg_class where oid in (2608,10723,10728,10738); relname | oid | reltype -------------------------+-------+--------- sql_features | 10723 | 10724 sql_implementation_info | 10728 | 10729 sql_packages | 10738 | 10739 pg_depend | 2608 | 10277 (4 rows) I also tried reindexing the table. postgres=# reindex table pg_statistic; ERROR: could not create unique index DETAIL: Table contains duplicated values. postgres=# Help! Paul
"Paul B. Anderson" <paul.a@pnlassociates.com> writes: > I did delete exactly one of each of these using ctid and the query then > shows no duplicates. But, the problem comes right back in the next > database-wide vacuum. That's pretty odd --- I'm inclined to suspect index corruption. > I also tried reindexing the table. Get rid of the duplicates (actually, I'd just blow away all the pg_statistic entries for each of these tables) and *then* reindex. Then re-analyze and see what happens. Worst case you could just delete everything in pg_statistic, reindex it, do a database-wide ANALYZE to repopulate it. By definition there's not any original data in that table... regards, tom lane
I removed the duplicates and then immediately reindexed. All is well. The vacuum analyze on the postgres database works now too. Thanks.
It is good to know the pg_statistic table can be emptied in case this ever happens again.
Paul
Tom Lane wrote:
It is good to know the pg_statistic table can be emptied in case this ever happens again.
Paul
Tom Lane wrote:
"Paul B. Anderson" <paul.a@pnlassociates.com> writes:I did delete exactly one of each of these using ctid and the query then shows no duplicates. But, the problem comes right back in the next database-wide vacuum.That's pretty odd --- I'm inclined to suspect index corruption.I also tried reindexing the table.Get rid of the duplicates (actually, I'd just blow away all the pg_statistic entries for each of these tables) and *then* reindex. Then re-analyze and see what happens. Worst case you could just delete everything in pg_statistic, reindex it, do a database-wide ANALYZE to repopulate it. By definition there's not any original data in that table... regards, tom lane .
Tom Lane wrote: > "Paul B. Anderson" <paul.a@pnlassociates.com> writes: >> I did delete exactly one of each of these using ctid and the query then >> shows no duplicates. But, the problem comes right back in the next >> database-wide vacuum. > > That's pretty odd --- I'm inclined to suspect index corruption. > >> I also tried reindexing the table. > > Get rid of the duplicates (actually, I'd just blow away all the > pg_statistic entries for each of these tables) and *then* reindex. > Then re-analyze and see what happens. > > Worst case you could just delete everything in pg_statistic, reindex it, > do a database-wide ANALYZE to repopulate it. By definition there's not > any original data in that table... > > regards, tom lane > > ---------------------------(end of broadcast)--------------------------- > TIP 4: Have you searched our list archives? > > http://archives.postgresql.org > Hello, newbe here.. I seem to have run across this same error. And I believe I can re-create it too. I'm running 8.1.4 on slackware-(almost 11). I have two scripts, one create's tables and indexes, the other has lots of "copy from stdin" statements. The very last line is VACUUM VERBOSE ANALYZE; which eventually gives me the same error. This is a test box, with test data, and this seemed to work: delete from pg_statistic; reindex table pg_statistic; vacuum analyze; So I'm ok, but I tried it again, by dropping the database and re-running both scripts and got the same error again. So thought I'd offer a test case if there was interest. The data is 46 meg compressed and 500'ish meg uncompressed. Its a little bit sensitive, so I'd like to be a little discreet with it, but can put it on a website for a developer to download. Please contact me privately for a link: andy@squeakycode.net ...Oh, also, this box has locked up on me a few times, so its not the most stable thing in the world. It did not lock up during import of this data, but there is flaky hardware in there someplace, so it could very well be a hardware issue. -Andy
andy <andy@squeakycode.net> writes: > So I'm ok, but I tried it again, by dropping the database and re-running > both scripts and got the same error again. So thought I'd offer a test > case if there was interest. Absolutely. I've seen just enough of these reports to make me think there's an underlying bug. regards, tom lane
Here are a couple of new data points on this issue.
Deleting all records in pg_statistic and then reindexing clears the problem but I've had the problem in two of my own databases in two separate postgresql instances as well as the postgres database in both instances.
I have a cluster of machines and the databases are on shared disk storage. I'm just getting this arrangement working and, while I've been debugging my scripts, I've accidentally had two copies of postgresql running against the same initdb directories at the same time on two different machines. Needless to say, this causes problems and I'm thinking that vacuuming in this condition may be at or near the root of the problem.
Paul
Tom Lane wrote:
Deleting all records in pg_statistic and then reindexing clears the problem but I've had the problem in two of my own databases in two separate postgresql instances as well as the postgres database in both instances.
I have a cluster of machines and the databases are on shared disk storage. I'm just getting this arrangement working and, while I've been debugging my scripts, I've accidentally had two copies of postgresql running against the same initdb directories at the same time on two different machines. Needless to say, this causes problems and I'm thinking that vacuuming in this condition may be at or near the root of the problem.
Paul
Tom Lane wrote:
andy <andy@squeakycode.net> writes:So I'm ok, but I tried it again, by dropping the database and re-running both scripts and got the same error again. So thought I'd offer a test case if there was interest.Absolutely. I've seen just enough of these reports to make me think there's an underlying bug. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to majordomo@postgresql.org so that your message can get through to the mailing list cleanly .
"Paul B. Anderson" <paul.a@pnlassociates.com> writes: > I have a cluster of machines and the databases are on shared disk > storage. I'm just getting this arrangement working and, while I've been > debugging my scripts, I've accidentally had two copies of postgresql > running against the same initdb directories at the same time on two > different machines. Needless to say, this causes problems and I'm > thinking that vacuuming in this condition may be at or near the root of > the problem. You're going to have much worse problems than this from that. Two postmasters modifying the same data files is a recipe for complete corruption. I would recommend abandoning any database you realize this has happened to: just initdb and start over. The chances of being able to fix it are minimal. regards, tom lane