Tom Lane 511e902b51 Make TRUNCATE ... RESTART IDENTITY restart sequences transactionally. ... In the previous coding, we simply issued ALTER SEQUENCE RESTART commands, which do not roll back on error. This meant that an error between truncating and committing left the sequences out of sync with the table contents, with potentially bad consequences as were noted in a Warning on the TRUNCATE man page. To fix, create a new storage file (relfilenode) for a sequence that is to be reset due to RESTART IDENTITY. If the transaction aborts, we'll automatically revert to the old storage file. This acts just like a rewriting ALTER TABLE operation. A penalty is that we have to take exclusive lock on the sequence, but since we've already got exclusive lock on its owning table, that seems unlikely to be much of a problem. The interaction of this with usual nontransactional behaviors of sequence operations is a bit weird, but it's hard to see what would be completely consistent. Our choice is to discard cached-but-unissued sequence values both when the RESTART is executed, and at rollback if any; but to not touch the currval() state either time. In passing, move the sequence reset operations to happen before not after any AFTER TRUNCATE triggers are fired. The previous ordering was not logically sensible, but was forced by the need to minimize inconsistency if the triggers caused an error. Transactional rollback is a much better solution to that. Patch by Steve Singer, rather heavily adjusted by me.		2010-11-17 16:42:18 -05:00
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adt	Add new buffers_backend_fsync field to pg_stat_bgwriter.	2010-11-15 12:42:59 -05:00
cache	Make TRUNCATE ... RESTART IDENTITY restart sequences transactionally.	2010-11-17 16:42:18 -05:00
error	Use appendStringInfoString() where appropriate in elog.c.	2010-11-04 15:28:35 -04:00
fmgr	Fix comparisons of pointers with zero to compare with NULL instead.	2010-10-29 15:51:52 -04:00
hash	Remove cvs keywords from all files.	2010-09-20 22:08:53 +02:00
init	Remove cvs keywords from all files.	2010-09-20 22:08:53 +02:00
mb	Improved parallel make support	2010-11-12 22:15:16 +02:00
misc	Make get_stack_depth_rlimit() handle RLIM_INFINITY more sanely.	2010-11-06 16:50:18 -04:00
mmgr	Remove cvs keywords from all files.	2010-09-20 22:08:53 +02:00
resowner	Remove cvs keywords from all files.	2010-09-20 22:08:53 +02:00
sort	Eliminate some repetitive coding in tuplesort.c.	2010-10-07 20:32:21 -04:00
time	Remove cvs keywords from all files.	2010-09-20 22:08:53 +02:00
.gitignore	Convert cvsignore to gitignore, and add .gitignore for build targets.	2010-09-22 12:57:04 +02:00
Gen_dummy_probes.sed	Remove cvs keywords from all files.	2010-09-20 22:08:53 +02:00
Gen_fmgrtab.pl	Remove cvs keywords from all files.	2010-09-20 22:08:53 +02:00
Makefile	Remove cvs keywords from all files.	2010-09-20 22:08:53 +02:00
probes.d	Remove cvs keywords from all files.	2010-09-20 22:08:53 +02:00