Re: URGENET: ALTER statement exectuation hangs when it is executed multiple time on a table
Tom Lane <[email protected]>
| Newsgroups | gmane.comp.db.postgresql.interfaces |
|---|---|
| Message-ID | <[email protected]> |
Dennis Wang <[email protected]> writes: > The actual PostgreSQL commands are: > ALTER TABLE warngrid ALTER COLUMN id SET DEFAULT (nextval('warngrid_seq')* 10)+1; > COPY warngrid FROM 'warngrid.csv' CSV HEADER; > ALTER TABLE warngrid ALTER COLUMN id DROP DEFAULT; > For the first time, these operation execute fine. Then I do these steps: > 4. delete all the records in the table > 5. rerun the shell script to copy records. > Then, the ALTER statement in step 1 hanging there. Did you do all this in one database session, or more than one? If the latter, maybe you haven't committed the transaction that did the DELETE? > I did check the lock state of the warngrid table, it says the process created by the ALTER statement hold an "AccessExclusiveLock" on the table. Did it actually *have* that lock, or was it waiting for it (granted = f in pg_locks)? regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 4: Have you searched our list archives? http://archives.postgresql.org