On 4/5/26 20:27, Melanie Plageman wrote: > On Fri, Apr 3, 2026 at 3:20 PM Tomas Vondra <[email protected]> wrote: >> >> I'm working on adding information about prefetching for scans [1], which >> includes BitmapHeapScan. I realized the instrumentation added by this >> thread may not be quite right, resulting in missing instrumentation for >> non-parallel-aware scans in a parallel query. >> >> A better description / explanation of the issue is posted here [2]. I've >> posted a proposed fix in the following message [3], in a patch: >> >> v8-0002-Show-Bitmap-Heap-Scan-stats-for-non-parallel-awar.patch >> >> I wonder if someone from this thread could review my analysis, and >> confirm this is not intentional. I don't see it discussed in the thread, >> so I assume no one noticed this behavior. I'd also appreciate a review >> of the proposed fix, or suggestions for alternative fixes. > > I can't imagine this was intentional. >
Indeed. > I reviewed your approach and suggest we aim for even lower impact by > always allocating the ParallelBitmapHeapState. That means the DSM > layout won't differ such that pcxt->toc has to point to the > instrumentation in the parallel-oblivious case and the pstate in the > parallel-aware case. Attached is a patch that does this. > I like this approach - it's much simpler / less invasive. It did not occur to me to use the parallel_aware in BitmapTableScanSetup. regards -- Tomas Vondra
