Re: BitmapHeapScan streaming read user and prelim refactoring

On 3/29/24 02:12, Thomas Munro wrote:
> On Fri, Mar 29, 2024 at 10:43 AM Tomas Vondra
> <tomas(dot)vondra(at)enterprisedb(dot)com> wrote:
>> I think there's some sort of bug, triggering this assert in heapam
>>
>> Assert(BufferGetBlockNumber(hscan->rs_cbuf) == tbmres->blockno);
>
> Thanks for the repro. I can't seem to reproduce it (still trying) but
> I assume this is with Melanie's v11 patch set which had
> v11-0016-v10-Read-Stream-API.patch.
>
> Would you mind removing that commit and instead applying the v13
> stream_read.c patches[1]? v10 stream_read.c was a little confused
> about random I/O combining, which I fixed with a small adjustment to
> the conditions for the "if" statement right at the end of
> read_stream_look_ahead(). Sorry about that. The fixed version, with
> eic=4, with your test query using WHERE a < a, ends its scan with:
>

I'll give that a try. Unfortunately unfortunately the v11 still has the
problem I reported about a week ago:

ERROR: prefetch and main iterators are out of sync

So I can't run the full benchmarks :-( but master vs. streaming read API
should work, I think.

regards

--
Tomas Vondra
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