Fix various typos and spelling mistakes in code comments

Author: Justin Pryzby
Discussion: https://postgr.es/m/20220411020336.GB26620@telsasoft.com

Author: david-rowley

contrib/ltree/ltree.h

@@ -24,7 +24,7 @@
  * modified to look for -D compile flags in Makefiles, so here, in order to
  * get the historic behavior of LOWER_NODE not being defined on MSVC, we only
  * define it when not building in that environment.  This is important as we
- * want to maintain the same LOWER_NODE behavior after a pg_update.
+ * want to maintain the same LOWER_NODE behavior after a pg_upgrade.
  */
 #ifndef _MSC_VER
 #define LOWER_NODE

src/backend/access/brin/brin_minmax_multi.c

@@ -310,7 +310,7 @@ AssertCheckRanges(Ranges *ranges, FmgrInfo *cmpFn, Oid colloid)
 	 */
 	AssertArrayOrder(cmpFn, colloid, ranges->values, 2 * ranges->nranges);
 
-	/* then the single-point ranges (with nvalues boundar values ) */
+	/* then the single-point ranges (with nvalues boundary values ) */
 	AssertArrayOrder(cmpFn, colloid, &ranges->values[2 * ranges->nranges],
 					 ranges->nsorted);
 

src/backend/access/heap/heapam.c

@@ -1470,7 +1470,7 @@ heap_getnextslot_tidrange(TableScanDesc sscan, ScanDirection direction,
 		 * heap_set_tidrange will have used heap_setscanlimits to limit the
 		 * range of pages we scan to only ones that can contain the TID range
 		 * we're scanning for.  Here we must filter out any tuples from these
-		 * pages that are outwith that range.
+		 * pages that are outside of that range.
 		 */
 		if (ItemPointerCompare(&scan->rs_ctup.t_self, mintid) < 0)
 		{

src/backend/access/transam/xlogreader.c

@@ -300,7 +300,7 @@ XLogReleasePreviousRecord(XLogReaderState *state)
 	/* Release the space. */
 	if (unlikely(record->oversized))
 	{
-		/* It's not in the the decode buffer, so free it to release space. */
+		/* It's not in the decode buffer, so free it to release space. */
 		pfree(record);
 	}
 	else

src/backend/access/transam/xlogrecovery.c

@@ -2975,7 +2975,7 @@ ReadRecord(XLogPrefetcher *xlogprefetcher, int emode,
 			/*
 			 * When not in standby mode we find that WAL ends in an incomplete
 			 * record, keep track of that record.  After recovery is done,
-			 * we'll write a record to indicate downstream WAL readers that
+			 * we'll write a record to indicate to downstream WAL readers that
 			 * that portion is to be ignored.
 			 */
 			if (!StandbyMode &&

src/backend/commands/dbcommands.c

@@ -386,7 +386,7 @@ ScanSourceDatabasePgClassPage(Page page, Buffer buf, Oid tbid, Oid dbid,
  * needs to be copied from the source database to the destination database,
  * and if so, construct a CreateDBRelInfo for it.
  *
- * Visbility checks are handled by the caller, so our job here is just
+ * Visibility checks are handled by the caller, so our job here is just
  * to assess the data stored in the tuple.
  */
 CreateDBRelInfo *

src/backend/commands/vacuumparallel.c

@@ -12,7 +12,7 @@
  * the memory space for storing dead items allocated in the DSM segment.  We
  * launch parallel worker processes at the start of parallel index
  * bulk-deletion and index cleanup and once all indexes are processed, the
- * parallel worker processes exit.  Each time we process indexes parallelly,
+ * parallel worker processes exit.  Each time we process indexes in parallel,
  * the parallel context is re-initialized so that the same DSM can be used for
  * multiple passes of index bulk-deletion and index cleanup.
  *

src/backend/executor/nodeMergeAppend.c

@@ -100,7 +100,7 @@ ExecInitMergeAppend(MergeAppend *node, EState *estate, int eflags)
 
 		/*
 		 * When no run-time pruning is required and there's at least one
-		 * subplan, we can fill as_valid_subplans immediately, preventing
+		 * subplan, we can fill ms_valid_subplans immediately, preventing
 		 * later calls to ExecFindMatchingSubPlans.
 		 */
 		if (!prunestate->do_exec_prune && nplans > 0)

src/backend/optimizer/path/costsize.c

@@ -1976,8 +1976,8 @@ compute_cpu_sort_cost(PlannerInfo *root, List *pathkeys, int nPresortedKeys,
 		 * by calling estimate_num_groups_incremental(), which estimates the
 		 * group size for "new" pathkeys.
 		 *
-		 * Note: estimate_num_groups_incremntal does not handle fake Vars, so use
-		 * a default estimate otherwise.
+		 * Note: estimate_num_groups_incremental does not handle fake Vars, so
+		 * use a default estimate otherwise.
 		 */
 		if (!has_fake_var)
 			nGroups = estimate_num_groups_incremental(root, pathkeyExprs,
@@ -6471,7 +6471,7 @@ compute_bitmap_pages(PlannerInfo *root, RelOptInfo *baserel, Path *bitmapqual,
 		exact_pages = heap_pages - lossy_pages;
 
 		/*
-		 * If there are lossy pages then recompute the  number of tuples
+		 * If there are lossy pages then recompute the number of tuples
 		 * processed by the bitmap heap node.  We assume here that the chance
 		 * of a given tuple coming from an exact page is the same as the
 		 * chance that a given page is exact.  This might not be true, but

src/backend/optimizer/path/pathkeys.c

@@ -2383,16 +2383,16 @@ pathkeys_useful_for_ordering(PlannerInfo *root, List *pathkeys)
  *		Count the number of pathkeys that are useful for grouping (instead of
  *		explicit sort)
  *
- * Group pathkeys could be reordered to benefit from the odering. The ordering
- * may not be "complete" and may require incremental sort, but that's fine. So
- * we simply count prefix pathkeys with a matching group key, and stop once we
- * find the first pathkey without a match.
+ * Group pathkeys could be reordered to benefit from the ordering. The
+ * ordering may not be "complete" and may require incremental sort, but that's
+ * fine. So we simply count prefix pathkeys with a matching group key, and
+ * stop once we find the first pathkey without a match.
  *
  * So e.g. with pathkeys (a,b,c) and group keys (a,b,e) this determines (a,b)
  * pathkeys are useful for grouping, and we might do incremental sort to get
  * path ordered by (a,b,e).
  *
- * This logic is necessary to retain paths with ordeding not matching grouping
+ * This logic is necessary to retain paths with ordering not matching grouping
  * keys directly, without the reordering.
  *
  * Returns the length of pathkey prefix with matching group keys.