Re: Streaming I/O, vectored I/O (WIP)

On Thu, Mar 28, 2024 at 9:43 AM Melanie Plageman
<melanieplageman(at)gmail(dot)com> wrote:
> For sequential scan, I added a little reset function to the streaming
> read API (read_stream_reset()) that just releases all the buffers.
> Previously, it set finished to true before releasing the buffers (to
> indicate it was done) and then set it back to false after. Now, I'll
> set distance to 0 before releasing the buffers and !0 after. I could
> just restore whatever value distance had before I set it to 0. Or I
> could set it to 1. But, thinking about it, are we sure we want to ramp
> up in the same way on rescans? Maybe we want to use some information
> from the previous scan to determine what to set distance to? Maybe I'm
> overcomplicating it...

I think 1 is good, as a rescan is even more likely to find the pages
in cache, and if that turns out to be wrong it'll very soon adjust.