I have been testing the postgresql Peer Direct port. I've used both the released binary and my own compiled version and get the same behavior. Please not that this is for testing purposes and I am not asking for support.
I'm running an import routine which moves records from a cobol database to postgres. This is strictly an import routine, where all queries are serialized. The postgres.conf file is set to defaults, except for fsync=false and the change in the WAL setting (see below). All sql statements are made using the libpq interface, and are simply create table followed by create index... followed by insert (repeat). Table sizes range from 0 to about 300k records, and there about 100 tables. Most of the tables have at least 10 fields, and all of the tables have at least one index, usually several. The client and the server are running on the same machine. There is no other activity on the database, and the import does not use transactions of any kind. About once in every 3000-5000 inserts, a new backend gets created without the previous one getting shut down. About 75% of the way though the process, too many backends get created and the import fails. The first time through, postmaster is reporting things like: DEBUG: Removing transaction log file 000000000000000000 DEBUG: XLogWrite: new log file created - consider increasing WAL_FILES Other times, I get the more ominous DEBUG: rename from C:\postgres\peer_direct\data/pg_xlog/0000000000000003 to C:\postgres\peer_direct\data/pg_xlog/000000000000000A (initialization of log file 0, segment 10) failed: Permission denied. If this happens about 10 times I will have about 7 backends up with 6 doing nothing and only 44k memory allocated for each. Killing the client app kills all the backends. The second time through I tried increasing the WAL files from 0 to eight. This did remove the XLogWrite: messages but did not fix the problem. There is not much point in turning fsync on because this would take too long. I could get the data in very easily with a preformatted copy, but I thought I'd pass this information along! Merlin ---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faqs/FAQ.html
