On Thursday, December 10, 2020 12:27 PM, Amit Kapila wrote: > On Thu, Dec 10, 2020 at 7:11 AM Kyotaro Horiguchi > <horikyota....@gmail.com> wrote: > > > > At Wed, 9 Dec 2020 16:27:30 +0530, Amit Kapila > > <amit.kapil...@gmail.com> wrote in > > > On Wed, Dec 9, 2020 at 6:32 AM Kyotaro Horiguchi > > > > Mmm. At least btree doesn't need to call smgrnblocks except at > > > > expansion, so we cannot get to the optimized path in major cases > > > > of truncation involving btree (and/or maybe other indexes). > > > > > > > > > > AFAICS, btree insert should call smgrnblocks via > > > > btree_xlog_insert->XLogReadBufferForRedo->XLogReadBufferForRedoExte > nded->XLogReadBufferExtended->smgrnblocks. > > > Similarly delete should also call smgrnblocks. Can you be bit more > > > specific related to the btree case you have in mind? > > > > Oh, sorry. I wrongly looked to non-recovery path. smgrnblocks is > > called during buffer loading while recovery. So, smgrnblock is called > > for indexes if any update happens on the heap relation. > > > > Okay, so this means that we can get the benefit of optimization in many cases > in the Truncate code path as well even if we use 'cached' > flag? If so, then I would prefer to keep the code consistent for both vacuum > and truncate recovery code path.
Yes, I have tested that optimization works for index relations. I have attached the V34, following the conditions that we use "cached" flag for both DropRelFileNodesBuffers() and DropRelFileNodesBuffers() for consistency. I added comment in 0004 the limitation of optimization when there are TOAST relations that use NON-PLAIN strategy. i.e. The optimization works if the data types used are integers, OID, bytea, etc. But for TOAST-able data types like text, the optimization will be skipped and force a full scan during recovery. Regards, Kirk Jamison
v34-0001-Prevent-invalidating-blocks-in-smgrextend-during.patch
Description: v34-0001-Prevent-invalidating-blocks-in-smgrextend-during.patch
v34-0002-Add-bool-param-in-smgrnblocks-for-cached-blocks.patch
Description: v34-0002-Add-bool-param-in-smgrnblocks-for-cached-blocks.patch
v34-0003-Optimize-DropRelFileNodeBuffers-during-recovery.patch
Description: v34-0003-Optimize-DropRelFileNodeBuffers-during-recovery.patch
v34-0004-Optimize-DropRelFileNodesAllBuffers-in-recovery.patch
Description: v34-0004-Optimize-DropRelFileNodesAllBuffers-in-recovery.patch
