diff --git a/src/backend/access/hash/hash_xlog.c b/src/backend/access/hash/hash_xlog.c
index 2e68303cbf..e88213c742 100644
--- a/src/backend/access/hash/hash_xlog.c
+++ b/src/backend/access/hash/hash_xlog.c
@@ -240,7 +240,6 @@ hash_xlog_add_ovfl_page(XLogReaderState *record)
 		{
 			Page		mappage = (Page) BufferGetPage(mapbuffer);
 			uint32	   *freep = NULL;
-			char	   *data;
 			uint32	   *bitmap_page_bit;
 
 			freep = HashPageGetBitmap(mappage);
diff --git a/src/backend/access/transam/multixact.c b/src/backend/access/transam/multixact.c
index 8f7d12950e..ec57f56adf 100644
--- a/src/backend/access/transam/multixact.c
+++ b/src/backend/access/transam/multixact.c
@@ -1614,7 +1614,6 @@ mXactCachePut(MultiXactId multi, int nmembers, MultiXactMember *members)
 	if (MXactCacheMembers++ >= MAX_CACHE_ENTRIES)
 	{
 		dlist_node *node;
-		mXactCacheEnt *entry;
 
 		node = dlist_tail_node(&MXactCache);
 		dlist_delete(node);
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 87b243e0d4..537845cada 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -3036,8 +3036,7 @@ XLogFileInitInternal(XLogSegNo logsegno, TimeLineID logtli,
 	pgstat_report_wait_start(WAIT_EVENT_WAL_INIT_SYNC);
 	if (pg_fsync(fd) != 0)
 	{
-		int			save_errno = errno;
-
+		save_errno = errno;
 		close(fd);
 		errno = save_errno;
 		ereport(ERROR,
@@ -4721,7 +4720,6 @@ XLogInitNewTimeline(TimeLineID endTLI, XLogRecPtr endOfLog, TimeLineID newTLI)
 
 		if (close(fd) != 0)
 		{
-			char		xlogfname[MAXFNAMELEN];
 			int			save_errno = errno;
 
 			XLogFileName(xlogfname, newTLI, startLogSegNo, wal_segment_size);
diff --git a/src/backend/commands/functioncmds.c b/src/backend/commands/functioncmds.c
index e7e37146f6..e6fcfc23b9 100644
--- a/src/backend/commands/functioncmds.c
+++ b/src/backend/commands/functioncmds.c
@@ -121,7 +121,6 @@ compute_return_type(TypeName *returnType, Oid languageOid,
 	{
 		char	   *typnam = TypeNameToString(returnType);
 		Oid			namespaceId;
-		AclResult	aclresult;
 		char	   *typname;
 		ObjectAddress address;
 
@@ -1112,8 +1111,6 @@ CreateFunction(ParseState *pstate, CreateFunctionStmt *stmt)
 	if (languageStruct->lanpltrusted)
 	{
 		/* if trusted language, need USAGE privilege */
-		AclResult	aclresult;
-
 		aclresult = pg_language_aclcheck(languageOid, GetUserId(), ACL_USAGE);
 		if (aclresult != ACLCHECK_OK)
 			aclcheck_error(aclresult, OBJECT_LANGUAGE,
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 9be04c8a1e..dacc989d85 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -16796,7 +16796,6 @@ PreCommit_on_commit_actions(void)
 	if (oids_to_drop != NIL)
 	{
 		ObjectAddresses *targetObjects = new_object_addresses();
-		ListCell   *l;
 
 		foreach(l, oids_to_drop)
 		{
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index dbdfe8bd2d..3670d1f186 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -233,8 +233,6 @@ ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel)
 	 */
 	if (!(params.options & VACOPT_ANALYZE))
 	{
-		ListCell   *lc;
-
 		foreach(lc, vacstmt->rels)
 		{
 			VacuumRelation *vrel = lfirst_node(VacuumRelation, lc);
diff --git a/src/backend/executor/execPartition.c b/src/backend/executor/execPartition.c
index ac03271882..901dd435ef 100644
--- a/src/backend/executor/execPartition.c
+++ b/src/backend/executor/execPartition.c
@@ -768,7 +768,6 @@ ExecInitPartitionInfo(ModifyTableState *mtstate, EState *estate,
 			{
 				List	   *onconflset;
 				List	   *onconflcols;
-				bool		found_whole_row;
 
 				/*
 				 * Translate expressions in onConflictSet to account for
diff --git a/src/backend/executor/nodeWindowAgg.c b/src/backend/executor/nodeWindowAgg.c
index 4b104c4d98..8b0858e9f5 100644
--- a/src/backend/executor/nodeWindowAgg.c
+++ b/src/backend/executor/nodeWindowAgg.c
@@ -2062,12 +2062,13 @@ ExecWindowAgg(PlanState *pstate)
 	if (winstate->all_first)
 	{
 		int			frameOptions = winstate->frameOptions;
-		ExprContext *econtext = winstate->ss.ps.ps_ExprContext;
 		Datum		value;
 		bool		isnull;
 		int16		len;
 		bool		byval;
 
+		econtext = winstate->ss.ps.ps_ExprContext;
+
 		if (frameOptions & FRAMEOPTION_START_OFFSET)
 		{
 			Assert(winstate->startOffset != NULL);
diff --git a/src/backend/lib/integerset.c b/src/backend/lib/integerset.c
index 5aff292c28..41d3abdb09 100644
--- a/src/backend/lib/integerset.c
+++ b/src/backend/lib/integerset.c
@@ -565,8 +565,6 @@ intset_is_member(IntegerSet *intset, uint64 x)
 	 */
 	if (intset->num_buffered_values > 0 && x >= intset->buffered_values[0])
 	{
-		int			itemno;
-
 		itemno = intset_binsrch_uint64(x,
 									   intset->buffered_values,
 									   intset->num_buffered_values,
diff --git a/src/backend/libpq/auth.c b/src/backend/libpq/auth.c
index 2e7330f7bc..10cd19e6cd 100644
--- a/src/backend/libpq/auth.c
+++ b/src/backend/libpq/auth.c
@@ -1652,8 +1652,6 @@ interpret_ident_response(const char *ident_response,
 						return false;
 					else
 					{
-						int			i;	/* Index into *ident_user */
-
 						cursor++;	/* Go over colon */
 						while (pg_isblank(*cursor))
 							cursor++;	/* skip blanks */
diff --git a/src/backend/optimizer/path/indxpath.c b/src/backend/optimizer/path/indxpath.c
index 7d176e7b00..045ff2e487 100644
--- a/src/backend/optimizer/path/indxpath.c
+++ b/src/backend/optimizer/path/indxpath.c
@@ -361,7 +361,6 @@ create_index_paths(PlannerInfo *root, RelOptInfo *rel)
 	if (bitjoinpaths != NIL)
 	{
 		List	   *all_path_outers;
-		ListCell   *lc;
 
 		/* Identify each distinct parameterization seen in bitjoinpaths */
 		all_path_outers = NIL;
@@ -2188,7 +2187,7 @@ match_clause_to_index(PlannerInfo *root,
 		/* Ignore duplicates */
 		foreach(lc, clauseset->indexclauses[indexcol])
 		{
-			IndexClause *iclause = (IndexClause *) lfirst(lc);
+			iclause = (IndexClause *) lfirst(lc);
 
 			if (iclause->rinfo == rinfo)
 				return;
diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c
index d929ce3417..079bd0bfdf 100644
--- a/src/backend/optimizer/plan/planner.c
+++ b/src/backend/optimizer/plan/planner.c
@@ -3484,8 +3484,6 @@ get_number_of_groups(PlannerInfo *root,
 
 			if (gd->hash_sets_idx)
 			{
-				ListCell   *lc;
-
 				gd->dNumHashGroups = 0;
 
 				groupExprs = get_sortgrouplist_exprs(parse->groupClause,
@@ -4720,8 +4718,6 @@ create_final_distinct_paths(PlannerInfo *root, RelOptInfo *input_rel,
 	Path	   *cheapest_input_path = input_rel->cheapest_total_path;
 	double		numDistinctRows;
 	bool		allow_hash;
-	Path	   *path;
-	ListCell   *lc;
 
 	/* Estimate number of distinct rows there will be */
 	if (parse->groupClause || parse->groupingSets || parse->hasAggs ||
@@ -4766,6 +4762,8 @@ create_final_distinct_paths(PlannerInfo *root, RelOptInfo *input_rel,
 		 * the other.)
 		 */
 		List	   *needed_pathkeys;
+		Path	   *path;
+		ListCell   *lc;
 
 		if (parse->hasDistinctOn &&
 			list_length(root->distinct_pathkeys) <
@@ -4776,7 +4774,7 @@ create_final_distinct_paths(PlannerInfo *root, RelOptInfo *input_rel,
 
 		foreach(lc, input_rel->pathlist)
 		{
-			Path	   *path = (Path *) lfirst(lc);
+			path = (Path *) lfirst(lc);
 
 			if (pathkeys_contained_in(needed_pathkeys, path->pathkeys))
 			{
@@ -5034,8 +5032,6 @@ create_ordered_paths(PlannerInfo *root,
 		 */
 		if (enable_incremental_sort && list_length(root->sort_pathkeys) > 1)
 		{
-			ListCell   *lc;
-
 			foreach(lc, input_rel->partial_pathlist)
 			{
 				Path	   *input_path = (Path *) lfirst(lc);
@@ -7607,7 +7603,6 @@ apply_scanjoin_target_to_paths(PlannerInfo *root,
 			AppendRelInfo **appinfos;
 			int			nappinfos;
 			List	   *child_scanjoin_targets = NIL;
-			ListCell   *lc;
 
 			Assert(child_rel != NULL);
 
diff --git a/src/backend/optimizer/plan/subselect.c b/src/backend/optimizer/plan/subselect.c
index df4ca12919..92e3338584 100644
--- a/src/backend/optimizer/plan/subselect.c
+++ b/src/backend/optimizer/plan/subselect.c
@@ -2554,8 +2554,6 @@ finalize_plan(PlannerInfo *root, Plan *plan,
 
 		case T_Append:
 			{
-				ListCell   *l;
-
 				foreach(l, ((Append *) plan)->appendplans)
 				{
 					context.paramids =
@@ -2571,8 +2569,6 @@ finalize_plan(PlannerInfo *root, Plan *plan,
 
 		case T_MergeAppend:
 			{
-				ListCell   *l;
-
 				foreach(l, ((MergeAppend *) plan)->mergeplans)
 				{
 					context.paramids =
@@ -2588,8 +2584,6 @@ finalize_plan(PlannerInfo *root, Plan *plan,
 
 		case T_BitmapAnd:
 			{
-				ListCell   *l;
-
 				foreach(l, ((BitmapAnd *) plan)->bitmapplans)
 				{
 					context.paramids =
@@ -2605,8 +2599,6 @@ finalize_plan(PlannerInfo *root, Plan *plan,
 
 		case T_BitmapOr:
 			{
-				ListCell   *l;
-
 				foreach(l, ((BitmapOr *) plan)->bitmapplans)
 				{
 					context.paramids =
@@ -2622,8 +2614,6 @@ finalize_plan(PlannerInfo *root, Plan *plan,
 
 		case T_NestLoop:
 			{
-				ListCell   *l;
-
 				finalize_primnode((Node *) ((Join *) plan)->joinqual,
 								  &context);
 				/* collect set of params that will be passed to right child */
diff --git a/src/backend/optimizer/prep/prepunion.c b/src/backend/optimizer/prep/prepunion.c
index 043181b586..71052c841d 100644
--- a/src/backend/optimizer/prep/prepunion.c
+++ b/src/backend/optimizer/prep/prepunion.c
@@ -653,7 +653,6 @@ generate_union_paths(SetOperationStmt *op, PlannerInfo *root,
 	if (partial_paths_valid)
 	{
 		Path	   *ppath;
-		ListCell   *lc;
 		int			parallel_workers = 0;
 
 		/* Find the highest number of workers requested for any subpath. */
diff --git a/src/backend/postmaster/autovacuum.c b/src/backend/postmaster/autovacuum.c
index 70a9176c54..b3b1afba86 100644
--- a/src/backend/postmaster/autovacuum.c
+++ b/src/backend/postmaster/autovacuum.c
@@ -1102,7 +1102,7 @@ rebuild_database_list(Oid newdb)
 		 */
 		for (i = 0; i < nelems; i++)
 		{
-			avl_dbase  *db = &(dbary[i]);
+			db = &(dbary[i]);
 
 			current_time = TimestampTzPlusMilliseconds(current_time,
 													   millis_increment);
diff --git a/src/backend/rewrite/rowsecurity.c b/src/backend/rewrite/rowsecurity.c
index a233dd4758..b2a7237430 100644
--- a/src/backend/rewrite/rowsecurity.c
+++ b/src/backend/rewrite/rowsecurity.c
@@ -824,7 +824,6 @@ add_with_check_options(Relation rel,
 		{
 			RowSecurityPolicy *policy = (RowSecurityPolicy *) lfirst(item);
 			Expr	   *qual = QUAL_FOR_WCO(policy);
-			WithCheckOption *wco;
 
 			if (qual != NULL)
 			{
diff --git a/src/backend/statistics/dependencies.c b/src/backend/statistics/dependencies.c
index c1c27e67d4..bf698c1fc3 100644
--- a/src/backend/statistics/dependencies.c
+++ b/src/backend/statistics/dependencies.c
@@ -1265,7 +1265,6 @@ dependency_is_compatible_expression(Node *clause, Index relid, List *statlist, N
 	else if (is_orclause(clause))
 	{
 		BoolExpr   *bool_expr = (BoolExpr *) clause;
-		ListCell   *lc;
 
 		/* start with no expression (we'll use the first match) */
 		*expr = NULL;
diff --git a/src/backend/utils/adt/rangetypes_spgist.c b/src/backend/utils/adt/rangetypes_spgist.c
index 1190b8000b..71a6053b6a 100644
--- a/src/backend/utils/adt/rangetypes_spgist.c
+++ b/src/backend/utils/adt/rangetypes_spgist.c
@@ -693,7 +693,6 @@ spg_range_quad_inner_consistent(PG_FUNCTION_ARGS)
 				 * quadrants if we're looking for a value strictly greater
 				 * than the maximum.
 				 */
-				int			cmp;
 
 				cmp = range_cmp_bounds(typcache, &centroidLower, maxLower);
 				if (cmp > 0 || (!inclusive && cmp == 0))
@@ -721,7 +720,6 @@ spg_range_quad_inner_consistent(PG_FUNCTION_ARGS)
 				 * quadrants if we're looking for a value strictly greater
 				 * than the maximum.
 				 */
-				int			cmp;
 
 				cmp = range_cmp_bounds(typcache, &centroidUpper, maxUpper);
 				if (cmp > 0 || (!inclusive && cmp == 0))
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 8280711f7e..9959f6910e 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -1303,7 +1303,6 @@ pg_get_indexdef_worker(Oid indexrelid, int colno,
 	if (!heap_attisnull(ht_idx, Anum_pg_index_indexprs, NULL))
 	{
 		Datum		exprsDatum;
-		bool		isnull;
 		char	   *exprsString;
 
 		exprsDatum = SysCacheGetAttr(INDEXRELID, ht_idx,
@@ -1500,7 +1499,6 @@ pg_get_indexdef_worker(Oid indexrelid, int colno,
 		{
 			Node	   *node;
 			Datum		predDatum;
-			bool		isnull;
 			char	   *predString;
 
 			/* Convert text string to node tree */
@@ -1945,7 +1943,6 @@ pg_get_partkeydef_worker(Oid relid, int prettyFlags,
 	if (!heap_attisnull(tuple, Anum_pg_partitioned_table_partexprs, NULL))
 	{
 		Datum		exprsDatum;
-		bool		isnull;
 		char	   *exprsString;
 
 		exprsDatum = SysCacheGetAttr(PARTRELID, tuple,
diff --git a/src/bin/pgbench/pgbench.c b/src/bin/pgbench/pgbench.c
index c0e907d437..07b7e0cf37 100644
--- a/src/bin/pgbench/pgbench.c
+++ b/src/bin/pgbench/pgbench.c
@@ -3109,7 +3109,6 @@ sendCommand(CState *st, Command *command)
 			for (j = 0; commands[j] != NULL; j++)
 			{
 				PGresult   *res;
-				char		name[MAX_PREPARE_NAME];
 
 				if (commands[j]->type != SQL_COMMAND)
 					continue;
@@ -3803,8 +3802,6 @@ advanceConnectionState(TState *thread, CState *st, StatsData *agg)
 				/* quickly skip commands until something to do... */
 				while (true)
 				{
-					Command    *command;
-
 					command = sql_script[st->use_file].commands[st->command];
 
 					/* cannot reach end of script in that state */
@@ -3959,8 +3956,6 @@ advanceConnectionState(TState *thread, CState *st, StatsData *agg)
 				 */
 				if (report_per_command)
 				{
-					Command    *command;
-
 					pg_time_now_lazy(&now);
 
 					command = sql_script[st->use_file].commands[st->command];