Although I'd misdiagnosed the reason for the recent failures on

tglsfdc · tglsfdc · commit 5e87ebb0c30f · 2007-09-22T04:40:03.000Z
buildfarm member grebe, I see no reason to revert the 1-byte-header-friendly
changes I made in varlena.c.  Instead, tweak the code a little bit to
get more advantage out of that.
diff --git a/src/backend/utils/adt/varlena.c b/src/backend/utils/adt/varlena.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/adt/varlena.c,v 1.158 2007/09/22 00:36:38 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/adt/varlena.c,v 1.159 2007/09/22 04:40:03 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -683,7 +683,7 @@ text_substring(Datum str, int32 start, int32 length, bool length_not_specified)
 		 * If we're working with an untoasted source, no need to do an
 		 * extra copying step.
 		 */
-		if (VARATT_IS_EXTENDED(str))
+		if (VARATT_IS_COMPRESSED(str) || VARATT_IS_EXTERNAL(str))
 			slice = DatumGetTextPSlice(str, slice_start, slice_size);
 		else
 			slice = (text *) DatumGetPointer(str);

Original file line number	Diff line number	Diff line change
`@@ -8,7 +8,7 @@`
`8`	`8`	`*`
`9`	`9`	`*`
`10`	`10`	`* IDENTIFICATION`
`11`		`- * $PostgreSQL: pgsql/src/backend/utils/adt/varlena.c,v 1.158 2007/09/22 00:36:38 tgl Exp $`
	`11`	`+ * $PostgreSQL: pgsql/src/backend/utils/adt/varlena.c,v 1.159 2007/09/22 04:40:03 tgl Exp $`
`12`	`12`	`*`
`13`	`13`	`*-------------------------------------------------------------------------`
`14`	`14`	`*/`
`@@ -683,7 +683,7 @@ text_substring(Datum str, int32 start, int32 length, bool length_not_specified)`
`683`	`683`	`* If we're working with an untoasted source, no need to do an`
`684`	`684`	`* extra copying step.`
`685`	`685`	`*/`
`686`		`- if (VARATT_IS_EXTENDED(str))`
	`686`	`+ if (VARATT_IS_COMPRESSED(str) \|\| VARATT_IS_EXTERNAL(str))`
`687`	`687`	`slice = DatumGetTextPSlice(str, slice_start, slice_size);`
`688`	`688`	`else`
`689`	`689`	`slice = (text *) DatumGetPointer(str);`