I noticed that a bulk INSERT into an empty table (which has been TRUNCATEd in the same transaction, for good measure) results in a curious number of open(2) calls for the FSM resource fork:
open("base/657862/16554373_fsm", O_RDWR) = -1 ENOENT (No such file or directory) lseek(17, 0, SEEK_END) = 407584768 write(17, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 8192) = 8192 lseek(18, 0, SEEK_END) = 333119488 write(18, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 8192) = 8192 lseek(18, 0, SEEK_END) = 333127680 write(18, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 8192) = 8192 open("base/657862/16554373_fsm", O_RDWR) = -1 ENOENT (No such file or directory) lseek(17, 0, SEEK_END) = 407592960 write(17, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 8192) = 8192 lseek(18, 0, SEEK_END) = 333135872 write(18, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 8192) = 8192 open("base/657862/16554373_fsm", O_RDWR) = -1 ENOENT (No such file or directory) lseek(17, 0, SEEK_END) = 407601152 write(17, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 8192) = 8192 lseek(18, 0, SEEK_END) = 333144064 write(18, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 8192) = 8192 lseek(18, 0, SEEK_END) = 333152256 write(18, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 8192) = 8192 open("base/657862/16554373_fsm", O_RDWR) = -1 ENOENT (No such file or directory) I'm not sure if this result in a significant performance hit on Linux (because the dentry cache covers negative lookups, too), but I suspect that it could be an issue with other systems. This happens with PostgreSQL 9.1.0. -- Florian Weimer <fwei...@bfk.de> BFK edv-consulting GmbH http://www.bfk.de/ Kriegsstraße 100 tel: +49-721-96201-1 D-76133 Karlsruhe fax: +49-721-96201-99 -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers