Allow to use HeapTupleData embedded in [Buffer]HeapTupleTableSlot.

anarazel · anarazel · commit 5408e233f066 · 2019-02-26T18:15:59.000-08:00
That avoids having to care about the lifetime of the HeapTupleHeaderData passed to ExecStore[Buffer]HeapTuple(). That doesn't make a huge difference for a plain HeapTupleTableSlot, but for BufferHeapTupleTableSlot it can be a significant advantage, avoiding the need to materialize slots where it's inconvenient to provide a HeapTupleData with appropriate lifetime to point to the on-disk tuple. It's quite possible that we'll want to add support functions for constructing HeapTuples using that embedded HeapTupleData, but for now callers do so themselves. Author: Andres Freund Discussion: https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.de
diff --git a/src/include/executor/tuptable.h b/src/include/executor/tuptable.h
@@ -16,6 +16,7 @@
 
 #include "access/htup.h"
 #include "access/tupdesc.h"
+#include "access/htup_details.h"
 #include "storage/buf.h"
 
 /*----------
@@ -246,6 +247,7 @@ typedef struct HeapTupleTableSlot
 	HeapTuple	tuple;		/* physical tuple */
 #define FIELDNO_HEAPTUPLETABLESLOT_OFF 2
 	uint32		off;		/* saved state for slot_deform_heap_tuple */
+	HeapTupleData tupdata;	/* optional workspace for storing tuple */
 } HeapTupleTableSlot;
 
 /* heap tuple residing in a buffer */
