5 files changed, 19 insertions, 24 deletions

diff --git a/src/backend/access/brin/brin_tuple.c b/src/backend/access/brin/brin_tuple.c
index ee05372f795..09e563b1f08 100644
--- a/src/backend/access/brin/brin_tuple.c
+++ b/src/backend/access/brin/brin_tuple.c
@@ -232,11 +232,10 @@ brin_form_tuple(BrinDesc *brdesc, BlockNumber blkno, BrinMemTuple *tuple,
 				 * same compression method. Otherwise we have to use the
 				 * default method.
 				 */
-				if (att->atttypid == atttype->type_id &&
-					CompressionMethodIsValid(att->attcompression))
+				if (att->atttypid == atttype->type_id)
 					compression = att->attcompression;
 				else
-					compression = GetDefaultToastCompression();
+					compression = InvalidCompressionMethod;
 
 				cvalue = toast_compress_datum(value, compression);
 
diff --git a/src/backend/access/common/indextuple.c b/src/backend/access/common/indextuple.c
index 52125604113..8df882da7a7 100644
--- a/src/backend/access/common/indextuple.c
+++ b/src/backend/access/common/indextuple.c
@@ -104,18 +104,9 @@ index_form_tuple(TupleDesc tupleDescriptor,
 			 att->attstorage == TYPSTORAGE_MAIN))
 		{
 			Datum		cvalue;
-			char		compression = att->attcompression;
 
-			/*
-			 * If the compression method is not valid, use the default. We
-			 * don't expect this to happen for regular index columns, which
-			 * inherit the setting from the corresponding table column, but we
-			 * do expect it to happen whenever an expression is indexed.
-			 */
-			if (!CompressionMethodIsValid(compression))
-				compression = GetDefaultToastCompression();
-
-			cvalue = toast_compress_datum(untoasted_values[i], compression);
+			cvalue = toast_compress_datum(untoasted_values[i],
+										  att->attcompression);
 
 			if (DatumGetPointer(cvalue) != NULL)
 			{
diff --git a/src/backend/access/common/toast_internals.c b/src/backend/access/common/toast_internals.c
index 8d2a9964c3f..c7b9ade5742 100644
--- a/src/backend/access/common/toast_internals.c
+++ b/src/backend/access/common/toast_internals.c
@@ -53,10 +53,12 @@ toast_compress_datum(Datum value, char cmethod)
 	Assert(!VARATT_IS_EXTERNAL(DatumGetPointer(value)));
 	Assert(!VARATT_IS_COMPRESSED(DatumGetPointer(value)));
 
-	Assert(CompressionMethodIsValid(cmethod));
-
 	valsize = VARSIZE_ANY_EXHDR(DatumGetPointer(value));
 
+	/* If the compression method is not valid, use the current default */
+	if (!CompressionMethodIsValid(cmethod))
+		cmethod = default_toast_compression;
+
 	/*
 	 * Call appropriate compression routine for the compression method.
 	 */
diff --git a/src/backend/access/common/tupdesc.c b/src/backend/access/common/tupdesc.c
index affbc509bdc..4c63bd4dc64 100644
--- a/src/backend/access/common/tupdesc.c
+++ b/src/backend/access/common/tupdesc.c
@@ -642,10 +642,7 @@ TupleDescInitEntry(TupleDesc desc,
 	att->attbyval = typeForm->typbyval;
 	att->attalign = typeForm->typalign;
 	att->attstorage = typeForm->typstorage;
-	if (IsStorageCompressible(typeForm->typstorage))
-		att->attcompression = GetDefaultToastCompression();
-	else
-		att->attcompression = InvalidCompressionMethod;
+	att->attcompression = InvalidCompressionMethod;
 	att->attcollation = typeForm->typcollation;
 
 	ReleaseSysCache(tuple);
@@ -711,7 +708,7 @@ TupleDescInitBuiltinEntry(TupleDesc desc,
 			att->attbyval = false;
 			att->attalign = TYPALIGN_INT;
 			att->attstorage = TYPSTORAGE_EXTENDED;
-			att->attcompression = GetDefaultToastCompression();
+			att->attcompression = InvalidCompressionMethod;
 			att->attcollation = DEFAULT_COLLATION_OID;
 			break;
 
diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index 8e6e8d51698..e2cd79ec546 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -2483,10 +2483,10 @@ reform_and_rewrite_tuple(HeapTuple tuple,
 			 * perform the compression here; we just need to decompress.  That
 			 * will trigger recompression later on.
 			 */
-
 			struct varlena *new_value;
 			ToastCompressionId cmid;
 			char		cmethod;
+			char		targetmethod;
 
 			new_value = (struct varlena *) DatumGetPointer(values[i]);
 			cmid = toast_get_compression_id(new_value);
@@ -2495,7 +2495,7 @@ reform_and_rewrite_tuple(HeapTuple tuple,
 			if (cmid == TOAST_INVALID_COMPRESSION_ID)
 				continue;
 
-			/* convert compression id to compression method */
+			/* convert existing compression id to compression method */
 			switch (cmid)
 			{
 				case TOAST_PGLZ_COMPRESSION_ID:
@@ -2506,10 +2506,16 @@ reform_and_rewrite_tuple(HeapTuple tuple,
 					break;
 				default:
 					elog(ERROR, "invalid compression method id %d", cmid);
+					cmethod = '\0'; /* keep compiler quiet */
 			}
 
+			/* figure out what the target method is */
+			targetmethod = TupleDescAttr(newTupDesc, i)->attcompression;
+			if (!CompressionMethodIsValid(targetmethod))
+				targetmethod = default_toast_compression;
+
 			/* if compression method doesn't match then detoast the value */
-			if (TupleDescAttr(newTupDesc, i)->attcompression != cmethod)
+			if (targetmethod != cmethod)
 			{
 				values[i] = PointerGetDatum(detoast_attr(new_value));
 				values_free[i] = true;