On Mon, Oct 29, 2012 at 12:17 AM, 高健 <luckyjackgao@xxxxxxxxx> wrote: > In src/backend/postmaster/bgwriter.c , I can find the following source > code(PostgreSQL9.2): > > > /* > * GUC parameters > */ > int BgWriterDelay = 200; The value hard coded into the C code is the starting value, or default. It is not a constant. Indeed, I don't think that value is even used. I think that upon start-up, that value gets set to the default listed in the guc.c file (which is also 200), and so the value listed in the bgwriter.c file is merely a mnemonic to remind people editing the file what the default value is. > But according to the fixed code of BgWriterDelay = 200, even when I update > bgwriter_delay in postgresql.conf to a different value(eg 300ms), > how can it ovewrite the fixed 200ms in bgwriter.c ? Doing so is the job of the "grand unified configuration" machinery, in src/backend/utils/misc/guc.c Cheers, Jeff -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
