ITAGAKI Takahiro wrote:
Andrew Dunstan <and...@dunslane.net> wrote:
I did this, but it turned out that the problem was a logic error that I
found once I had managed to get a working debugger. However, the Windows
thread code should now be more robust, so thanks to Andrew and Magnus
for the suggestions.
Hello, I tested parallel restore on Windows.
I have some random comments about it:
Thanks for this
* Two compiler warnings.
pg_backup_custom.c: In function `_PrintTocData':
pg_backup_custom.c:437: warning: unused variable `ctx'
pg_backup_custom.c: In function `_ReopenArchive':
pg_backup_custom.c:849: warning: unused variable `ctx'
Will be fixed in code cleanup
* No description about new options in pg_restore --help.
There are no help messages about multi-thread (-m) and
truncate-before-load options.
Will fix
* multi-thread option is ignored if --data-only is on.
Is it an intended behavior? Even if so, we'd better to have
warning messages here.
Not intended, unless my memory is fading. I will check.
* Threads, forked processes and connections are disposed per entry.
I think it's a designed behavior, but there might be room for
improvement. The present implementation is slower when there
are many small objects. If we can specialize in thread-based
implementation, thread pooling and connections pooling are
typically used in the context. -- it might be a ToDo item in 8.5.
Yes. I only got threading working at all just a few days ago. I think
your suggestion is a good one, and we should probably converge on a
threaded implementation and then look at using pooling. However, as you
say that would be work for the 8.5 timeframe.
----
I have no idea about performance because I don't have multi-core
machine for windows. Parallel restore seems to be slower than
serial restore on single-cpu machine.
Not surprising. There is extra connection, worker setup/breakdown,
dependency housekeeping and context switching involved. However, I'd be
surprised if the overhead were huge.
cheers
andrew
--
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers
