kosalalakshitha
diff --git a/‎src/backend/access/common/printtup.c
Lines changed: 18 additions & 0 deletions b/‎src/backend/access/common/printtup.c
Lines changed: 18 additions & 0 deletions
diff --git a/‎src/backend/storage/page/bufpage.c
Lines changed: 15 additions & 0 deletions b/‎src/backend/storage/page/bufpage.c
Lines changed: 15 additions & 0 deletions
diff --git a/‎src/backend/tcop/postgres.c
Lines changed: 5 additions & 0 deletions b/‎src/backend/tcop/postgres.c
Lines changed: 5 additions & 0 deletions
@@ -20,6 +20,7 @@
 #include "libpq/pqformat.h"
 #include "tcop/pquery.h"
 #include "utils/lsyscache.h"
+#include "utils/memdebug.h"
 
 
 static void printtup_startup(DestReceiver *self, int operation,
@@ -324,9 +325,26 @@ printtup(TupleTableSlot *slot, DestReceiver *self)
 		/*
 		 * If we have a toasted datum, forcibly detoast it here to avoid
 		 * memory leakage inside the type's output routine.
+		 *
+		 * Here we catch undefined bytes in tuples that are returned to the
+		 * client without hitting disk; see comments at the related check in
+		 * PageAddItem().  Whether to test before or after detoast is somewhat
+		 * arbitrary, as is whether to test external/compressed data at all.
+		 * Undefined bytes in the pre-toast datum will have triggered Valgrind
+		 * errors in the compressor or toaster; any error detected here for
+		 * such datums would indicate an (unlikely) bug in a type-independent
+		 * facility.  Therefore, this test is most useful for uncompressed,
+		 * non-external datums.
+		 *
+		 * We don't presently bother checking non-varlena datums for undefined
+		 * data.  PageAddItem() does check them.
 		 */
 		if (thisState->typisvarlena)
+		{
+			VALGRIND_CHECK_MEM_IS_DEFINED(origattr, VARSIZE_ANY(origattr));
+
 			attr = PointerGetDatum(PG_DETOAST_DATUM(origattr));
+		}
 		else
 			attr = origattr;
 
 
@@ -17,6 +17,7 @@
 #include "access/htup_details.h"
 #include "access/xlog.h"
 #include "storage/checksum.h"
+#include "utils/memdebug.h"
 #include "utils/memutils.h"
 
 
@@ -297,6 +298,20 @@ PageAddItem(Page page,
 	/* set the item pointer */
 	ItemIdSetNormal(itemId, upper, size);
 
+	/*
+	 * Items normally contain no uninitialized bytes.  Core bufpage consumers
+	 * conform, but this is not a necessary coding rule; a new index AM could
+	 * opt to depart from it.  However, data type input functions and other
+	 * C-language functions that synthesize datums should initialize all
+	 * bytes; datumIsEqual() relies on this.  Testing here, along with the
+	 * similar check in printtup(), helps to catch such mistakes.
+	 *
+	 * Values of the "name" type retrieved via index-only scans may contain
+	 * uninitialized bytes; see comment in btrescan().  Valgrind will report
+	 * this as an error, but it is safe to ignore.
+	 */
+	VALGRIND_CHECK_MEM_IS_DEFINED(item, size);
+
 	/* copy the item's data onto the page */
 	memcpy((char *) page + upper, item, size);
 
 
@@ -69,6 +69,7 @@
 #include "tcop/tcopprot.h"
 #include "tcop/utility.h"
 #include "utils/lsyscache.h"
+#include "utils/memdebug.h"
 #include "utils/memutils.h"
 #include "utils/ps_status.h"
 #include "utils/snapmgr.h"
@@ -846,6 +847,10 @@ exec_simple_query(const char *query_string)
 
 	TRACE_POSTGRESQL_QUERY_START(query_string);
 
+#ifdef USE_VALGRIND
+	VALGRIND_PRINTF("statement: %s\n", query_string);
+#endif
+
 	/*
 	 * We use save_log_statement_stats so ShowUsage doesn't report incorrect
 	 * results because ResetUsage wasn't called.