On Wed, 10 Apr 2019 11:55:51 -0700 Andres Freund <and...@anarazel.de> wrote:
> Hi, > > On 2019-04-10 14:38:43 -0400, Robert Haas wrote: > > On Wed, Apr 10, 2019 at 2:21 PM Jehan-Guillaume de Rorthais > > <j...@dalibo.com> wrote: > > > In my current design, the scan is done backward from end to start and I > > > keep all the records appearing after the last occurrence of their > > > respective FPI. > > > > Oh, interesting. That seems like it would require pretty major > > surgery on the WAL stream. > > Can't you just read each segment forward, and then reverse? Not sure what you mean. I first look for the very last XLOG record by jumping to the last WAL and scanning it forward. Then, I do a backward from there to record LSN of xlogrecord to keep. Finally, I clone each WAL and edit them as needed (as described in my previous email). This is my current WIP though. > That's not that much memory? I don't know, yet. I did not mesure it.
