Thanks for the replies. On Tue, May 12, 2020 at 2:04 PM Michael Paquier <mich...@paquier.xyz> wrote:
> On Tue, May 12, 2020 at 12:55:37PM +0900, Fujii Masao wrote: > > On 2020/05/12 9:42, Paul Guo wrote: > >> 1. StartupXLOG() does fsync on the whole data directory early in > >> the crash recovery. I'm wondering if we could skip some > >> directories (at least the pg_log/, table directories) since wal, > >> etc could ensure consistency. > > > > I agree that we can skip log directory but I'm not sure if skipping > > table directory is really safe. Also ISTM that we can skip the > directories > > that those contents are removed or zeroed during recovery, > > for example, pg_snapshots, pg_substrans, etc. > > Basically excludeDirContents[] as of basebackup.c. > table directories & wal fsync probably dominates the fsync time. Do we know any possible real scenario that requires table directory fsync?
