v03_0001-Added-offset-with-block-number-in-vacuum-errcontext.patch

From 182efbd015a208fa659e48a984c82ab9e418eb81 Mon Sep 17 00:00:00 2001
From: Mahendra Singh Thalor <mahi6run@gmail.com>
Date: Fri, 31 Jul 2020 23:48:40 -0700
Subject: [PATCH] Added offset with block number in vacuum errcontext

---
 src/backend/access/heap/vacuumlazy.c | 67 +++++++++++++++++++++-------
 1 file changed, 50 insertions(+), 17 deletions(-)

diff --git a/src/backend/access/heap/vacuumlazy.c b/src/backend/access/heap/vacuumlazy.c
index 1bbc4598f7..b6015c9297 100644
--- a/src/backend/access/heap/vacuumlazy.c
+++ b/src/backend/access/heap/vacuumlazy.c
@@ -316,6 +316,7 @@ typedef struct LVRelStats
 	/* Used for error callback */
 	char	   *indname;
 	BlockNumber blkno;			/* used only for heap operations */
+	OffsetNumber	offnum;
 	VacErrPhase phase;
 } LVRelStats;
 
@@ -323,6 +324,7 @@ typedef struct LVRelStats
 typedef struct LVSavedErrInfo
 {
 	BlockNumber blkno;
+	OffsetNumber	offnum;
 	VacErrPhase phase;
 } LVSavedErrInfo;
 
@@ -341,7 +343,8 @@ static void lazy_scan_heap(Relation onerel, VacuumParams *params,
 						   LVRelStats *vacrelstats, Relation *Irel, int nindexes,
 						   bool aggressive);
 static void lazy_vacuum_heap(Relation onerel, LVRelStats *vacrelstats);
-static bool lazy_check_needs_freeze(Buffer buf, bool *hastup);
+static bool lazy_check_needs_freeze(Buffer buf, bool *hastup,
+									LVRelStats *vacrelstats);
 static void lazy_vacuum_all_indexes(Relation onerel, Relation *Irel,
 									IndexBulkDeleteResult **stats,
 									LVRelStats *vacrelstats, LVParallelState *lps,
@@ -364,6 +367,7 @@ static void lazy_record_dead_tuple(LVDeadTuples *dead_tuples,
 static bool lazy_tid_reaped(ItemPointer itemptr, void *state);
 static int	vac_cmp_itemptr(const void *left, const void *right);
 static bool heap_page_is_all_visible(Relation rel, Buffer buf,
+									 LVRelStats *vacrelstats,
 									 TransactionId *visibility_cutoff_xid, bool *all_frozen);
 static void lazy_parallel_vacuum_indexes(Relation *Irel, IndexBulkDeleteResult **stats,
 										 LVRelStats *vacrelstats, LVParallelState *lps,
@@ -396,7 +400,8 @@ static LVSharedIndStats *get_indstats(LVShared *lvshared, int n);
 static bool skip_parallel_vacuum_index(Relation indrel, LVShared *lvshared);
 static void vacuum_error_callback(void *arg);
 static void update_vacuum_error_info(LVRelStats *errinfo, LVSavedErrInfo *saved_err_info,
-									 int phase, BlockNumber blkno);
+									 int phase, BlockNumber blkno,
+									 OffsetNumber offnum);
 static void restore_vacuum_error_info(LVRelStats *errinfo, const LVSavedErrInfo *saved_err_info);
 
 
@@ -547,7 +552,8 @@ heap_vacuum_rel(Relation onerel, VacuumParams *params,
 		 * revert to the previous phase.
 		 */
 		update_vacuum_error_info(vacrelstats, NULL, VACUUM_ERRCB_PHASE_TRUNCATE,
-								 vacrelstats->nonempty_pages);
+								 vacrelstats->nonempty_pages,
+								 InvalidOffsetNumber);
 		lazy_truncate_heap(onerel, vacrelstats);
 	}
 
@@ -957,7 +963,7 @@ lazy_scan_heap(Relation onerel, VacuumParams *params, LVRelStats *vacrelstats,
 		pgstat_progress_update_param(PROGRESS_VACUUM_HEAP_BLKS_SCANNED, blkno);
 
 		update_vacuum_error_info(vacrelstats, NULL, VACUUM_ERRCB_PHASE_SCAN_HEAP,
-								 blkno);
+								 blkno, InvalidOffsetNumber);
 
 		if (blkno == next_unskippable_block)
 		{
@@ -1126,7 +1132,7 @@ lazy_scan_heap(Relation onerel, VacuumParams *params, LVRelStats *vacrelstats,
 			 * to use lazy_check_needs_freeze() for both situations, though.
 			 */
 			LockBuffer(buf, BUFFER_LOCK_SHARE);
-			if (!lazy_check_needs_freeze(buf, &hastup))
+			if (!lazy_check_needs_freeze(buf, &hastup, vacrelstats))
 			{
 				UnlockReleaseBuffer(buf);
 				vacrelstats->scanned_pages++;
@@ -1263,6 +1269,7 @@ lazy_scan_heap(Relation onerel, VacuumParams *params, LVRelStats *vacrelstats,
 		{
 			ItemId		itemid;
 
+			vacrelstats->offnum = offnum;
 			itemid = PageGetItemId(page, offnum);
 
 			/* Unused items require no processing, but we count 'em */
@@ -1836,7 +1843,7 @@ lazy_vacuum_heap(Relation onerel, LVRelStats *vacrelstats)
 
 	/* Update error traceback information */
 	update_vacuum_error_info(vacrelstats, &saved_err_info, VACUUM_ERRCB_PHASE_VACUUM_HEAP,
-							 InvalidBlockNumber);
+							 InvalidBlockNumber, InvalidOffsetNumber);
 
 	pg_rusage_init(&ru0);
 	npages = 0;
@@ -1915,7 +1922,7 @@ lazy_vacuum_page(Relation onerel, BlockNumber blkno, Buffer buffer,
 
 	/* Update error traceback information */
 	update_vacuum_error_info(vacrelstats, &saved_err_info, VACUUM_ERRCB_PHASE_VACUUM_HEAP,
-							 blkno);
+							 blkno, InvalidOffsetNumber);
 
 	START_CRIT_SECTION();
 
@@ -1967,7 +1974,8 @@ lazy_vacuum_page(Relation onerel, BlockNumber blkno, Buffer buffer,
 	 * dirty, exclusively locked, and, if needed, a full page image has been
 	 * emitted in the log_heap_clean() above.
 	 */
-	if (heap_page_is_all_visible(onerel, buffer, &visibility_cutoff_xid,
+	if (heap_page_is_all_visible(onerel, buffer, vacrelstats,
+								 &visibility_cutoff_xid,
 								 &all_frozen))
 		PageSetAllVisible(page);
 
@@ -2006,12 +2014,13 @@ lazy_vacuum_page(Relation onerel, BlockNumber blkno, Buffer buffer,
  * Also returns a flag indicating whether page contains any tuples at all.
  */
 static bool
-lazy_check_needs_freeze(Buffer buf, bool *hastup)
+lazy_check_needs_freeze(Buffer buf, bool *hastup, LVRelStats *vacrelstats)
 {
 	Page		page = BufferGetPage(buf);
 	OffsetNumber offnum,
 				maxoff;
 	HeapTupleHeader tupleheader;
+	LVSavedErrInfo saved_err_info;
 
 	*hastup = false;
 
@@ -2024,6 +2033,11 @@ lazy_check_needs_freeze(Buffer buf, bool *hastup)
 	if (PageIsNew(page) || PageIsEmpty(page))
 		return false;
 
+	/* Update error traceback information */
+	update_vacuum_error_info(vacrelstats, &saved_err_info,
+			VACUUM_ERRCB_PHASE_SCAN_HEAP, vacrelstats->blkno,
+			InvalidOffsetNumber);
+
 	maxoff = PageGetMaxOffsetNumber(page);
 	for (offnum = FirstOffsetNumber;
 		 offnum <= maxoff;
@@ -2031,6 +2045,7 @@ lazy_check_needs_freeze(Buffer buf, bool *hastup)
 	{
 		ItemId		itemid;
 
+		vacrelstats->offnum = offnum;
 		itemid = PageGetItemId(page, offnum);
 
 		/* this should match hastup test in count_nondeletable_pages() */
@@ -2045,10 +2060,13 @@ lazy_check_needs_freeze(Buffer buf, bool *hastup)
 
 		if (heap_tuple_needs_freeze(tupleheader, FreezeLimit,
 									MultiXactCutoff, buf))
-			return true;
+			break;
 	}							/* scan along page */
 
-	return false;
+	/* Revert to the previous phase information for error traceback */
+	restore_vacuum_error_info(vacrelstats, &saved_err_info);
+
+	return offnum <= maxoff ? true : false;
 }
 
 /*
@@ -2426,7 +2444,7 @@ lazy_vacuum_index(Relation indrel, IndexBulkDeleteResult **stats,
 	vacrelstats->indname = pstrdup(RelationGetRelationName(indrel));
 	update_vacuum_error_info(vacrelstats, &saved_err_info,
 							 VACUUM_ERRCB_PHASE_VACUUM_INDEX,
-							 InvalidBlockNumber);
+							 InvalidBlockNumber, InvalidOffsetNumber);
 
 	/* Do bulk deletion */
 	*stats = index_bulk_delete(&ivinfo, *stats,
@@ -2486,11 +2504,11 @@ lazy_cleanup_index(Relation indrel,
 	vacrelstats->indname = pstrdup(RelationGetRelationName(indrel));
 	update_vacuum_error_info(vacrelstats, &saved_err_info,
 							 VACUUM_ERRCB_PHASE_INDEX_CLEANUP,
-							 InvalidBlockNumber);
+							 InvalidBlockNumber, InvalidOffsetNumber);
 
 	*stats = index_vacuum_cleanup(&ivinfo, *stats);
 
-	/* Revert back to the old phase information for error traceback */
+	/* Revert to the old phase information for error traceback */
 	restore_vacuum_error_info(vacrelstats, &saved_err_info);
 	pfree(vacrelstats->indname);
 	vacrelstats->indname = NULL;
@@ -2640,6 +2658,7 @@ lazy_truncate_heap(Relation onerel, LVRelStats *vacrelstats)
 		 */
 		new_rel_pages = count_nondeletable_pages(onerel, vacrelstats);
 		vacrelstats->blkno = new_rel_pages;
+		vacrelstats->offnum = InvalidOffsetNumber;
 
 		if (new_rel_pages >= old_rel_pages)
 		{
@@ -2952,6 +2971,7 @@ vac_cmp_itemptr(const void *left, const void *right)
  */
 static bool
 heap_page_is_all_visible(Relation rel, Buffer buf,
+						 LVRelStats *vacrelstats,
 						 TransactionId *visibility_cutoff_xid,
 						 bool *all_frozen)
 {
@@ -2976,6 +2996,7 @@ heap_page_is_all_visible(Relation rel, Buffer buf,
 		ItemId		itemid;
 		HeapTupleData tuple;
 
+		vacrelstats->offnum = offnum;
 		itemid = PageGetItemId(page, offnum);
 
 		/* Unused or redirect line pointers are of no interest */
@@ -3574,14 +3595,22 @@ vacuum_error_callback(void *arg)
 	{
 		case VACUUM_ERRCB_PHASE_SCAN_HEAP:
 			if (BlockNumberIsValid(errinfo->blkno))
-				errcontext("while scanning block %u of relation \"%s.%s\"",
-						   errinfo->blkno, errinfo->relnamespace, errinfo->relname);
+			{
+				if (OffsetNumberIsValid(errinfo->offnum))
+					errcontext("while scanning block %u of relation \"%s.%s\", item offset %u",
+							   errinfo->blkno, errinfo->relnamespace, errinfo->relname, errinfo->offnum);
+				else
+					errcontext("while scanning block %u of relation \"%s.%s\"",
+							   errinfo->blkno, errinfo->relnamespace, errinfo->relname);
+			}
 			break;
 
 		case VACUUM_ERRCB_PHASE_VACUUM_HEAP:
 			if (BlockNumberIsValid(errinfo->blkno))
+			{
 				errcontext("while vacuuming block %u of relation \"%s.%s\"",
 						   errinfo->blkno, errinfo->relnamespace, errinfo->relname);
+			}
 			break;
 
 		case VACUUM_ERRCB_PHASE_VACUUM_INDEX:
@@ -3589,6 +3618,7 @@ vacuum_error_callback(void *arg)
 					   errinfo->indname, errinfo->relnamespace, errinfo->relname);
 			break;
 
+
 		case VACUUM_ERRCB_PHASE_INDEX_CLEANUP:
 			errcontext("while cleaning up index \"%s\" of relation \"%s.%s\"",
 					   errinfo->indname, errinfo->relnamespace, errinfo->relname);
@@ -3613,15 +3643,17 @@ vacuum_error_callback(void *arg)
  */
 static void
 update_vacuum_error_info(LVRelStats *errinfo, LVSavedErrInfo *saved_err_info, int phase,
-						 BlockNumber blkno)
+						 BlockNumber blkno, OffsetNumber offnum)
 {
 	if (saved_err_info)
 	{
+		saved_err_info->offnum = errinfo->offnum;
 		saved_err_info->blkno = errinfo->blkno;
 		saved_err_info->phase = errinfo->phase;
 	}
 
 	errinfo->blkno = blkno;
+	errinfo->offnum = offnum;
 	errinfo->phase = phase;
 }
 
@@ -3632,5 +3664,6 @@ static void
 restore_vacuum_error_info(LVRelStats *errinfo, const LVSavedErrInfo *saved_err_info)
 {
 	errinfo->blkno = saved_err_info->blkno;
+	errinfo->offnum = saved_err_info->offnum;
 	errinfo->phase = saved_err_info->phase;
 }
-- 
2.17.1