On Thu, Oct 24, 2024 at 3:45 AM Melanie Plageman <melanieplage...@gmail.com> wrote:
> Hi, > > HeapScanDescData->rs_cindex (the current index into the array of > visible tuples stored in the heap scan descriptor) is used for > multiple scan types, but for bitmap heap scans, AFAICT, it should > never be < 0. > > As such, I find this test in heapam_scan_bitmap_next_tuple() pretty > confusing. > > if (hscan->rs_cindex < 0 || hscan->rs_cindex >= hscan->rs_ntuples) > > I know it seems innocuous, but I find it pretty distracting. Am I > missing something? Could it somehow be < 0? > > If not, I propose removing that part of the if statement like in the > attached patch. > > You are right it can never be < 0 in this case at least. In fact you don't need to explicitly set it to 0 in initscan[1], because before calling heapam_scan_bitmap_next_tuple() we must call heapam_scan_bitmap_next_block() and this function is initializing this to 0 (hscan->rs_cindex = 0;). Anyway no object even if you prefer to initialize in initscan(), just the point is that we are already doing it for each block before fetching tuples from the block. [1] @@ -378,6 +378,7 @@ initscan(HeapScanDesc scan, ScanKey key, bool keep_startblock) ItemPointerSetInvalid(&scan->rs_ctup.t_self); scan->rs_cbuf = InvalidBuffer; scan->rs_cblock = InvalidBlockNumber; + scan->rs_cindex = 0; -- Regards, Dilip Kumar EnterpriseDB: http://www.enterprisedb.com
