On Wed, Jul 14, 2021 at 06:04:14PM +0300, Heikki Linnakangas wrote: > On 14/07/2021 15:12, vignesh C wrote: > > On Sat, Jan 23, 2021 at 3:49 AM Heikki Linnakangas <hlinnaka@iki.fi> wrote: > > > Here's an updated version that fixes one bug: > > > > > > The CFBot was reporting a failure on the FreeBSD system [1]. It turned > > > out to be an out-of-memory issue caused by an underflow bug in the > > > calculation of the size of the tape read buffer size. With a small > > > work_mem size, the memory left for tape buffers was negative, and that > > > wrapped around to a very large number. I believe that was not caught by > > > the other systems, because the other ones had enough memory for the > > > incorrectly-sized buffers anyway. That was the case on my laptop at > > > least. It did cause a big slowdown in the 'tuplesort' regression test > > > though, which I hadn't noticed. > > > > > > The fix for that bug is here as a separate patch for easier review, but > > > I'll squash it before committing. > > > > The patch does not apply on Head anymore, could you rebase and post a > > patch. I'm changing the status to "Waiting for Author". > > Here's a rebased version. I also squashed that little bug fix from previous > patch set. >
Hi,
This patch does not apply, can you submit a rebased version?
-- Jaime Casanova Director de Servicios Profesionales SystemGuards - Consultores de PostgreSQL
Hi,
+ * Before PostgreSQL 14, we used the polyphase merge algorithm (Knuth's
+ * Algorithm 5.4.2D),
I think the above 'Before PostgreSQL 14' should be 'Before PostgreSQL 15' now that PostgreSQL 14 has been released.
+static int64 +merge_read_buffer_size(int64 avail_mem, int nInputTapes, int nInputRuns, + int maxOutputTapes)
For memory to allocate, I think uint64 can be used (instead of int64).