Re: Read-ahead and parallelism in redo recovery

[Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>]

Decibel! <decibel(at)decibel(dot)org> writes:
> Perhaps a good short-term measure would be to have recovery allocate  
> a 16M buffer and read in entire xlog files at once.

If that isn't entirely useless, you need a better kernel.  The system
should *certainly* be bright enough to do read-ahead for our reads of
the source xlog file.  The fetches that are likely to be problematic are
the ones for pages in the data area, which will be a lot less regular
for typical workloads.

			regards, tom lane