@@ -141,7 +141,8 @@ booloptimize_bounded_sort = true;
141141 * which is a separate palloc chunk --- we assume it is just one chunk and
142142 * can be freed by a simple pfree() (except during merge, when we use a
143143 * simple slab allocator). SortTuples also contain the tuple's first key
144- * column in Datum/nullflag format, and an index integer.
144+ * column in Datum/nullflag format, and a source/input tape number that
145+ * tracks which tape each heap element/slot belongs to during merging.
145146 *
146147 * Storing the first key column lets us save heap_getattr or index_getattr
147148 * calls during tuple comparisons. We could extract and save all the key
@@ -162,16 +163,13 @@ booloptimize_bounded_sort = true;
162163 * either the same pointer as "tuple", or is an abbreviated key value as
163164 * described above. Accordingly, "tuple" is always used in preference to
164165 * datum1 as the authoritative value for pass-by-reference cases.
165- *
166- * tupindex holds the input tape number that each tuple in the heap was read
167- * from during merge passes.
168166 */
169167typedef struct
170168{
171169void * tuple ;/* the tuple itself */
172170Datum datum1 ;/* value of first key column */
173171bool isnull1 ;/* is first key column NULL? */
174- int tupindex ;/*see notes above */
172+ int srctape ;/*source tape number */
175173}SortTuple ;
176174
177175/*
@@ -2093,7 +2091,7 @@ tuplesort_gettuple_common(Tuplesortstate *state, bool forward,
20932091 */
20942092if (state -> memtupcount > 0 )
20952093{
2096- int srcTape = state -> memtuples [0 ].tupindex ;
2094+ int srcTape = state -> memtuples [0 ].srctape ;
20972095SortTuple newtup ;
20982096
20992097* stup = state -> memtuples [0 ];
@@ -2124,7 +2122,7 @@ tuplesort_gettuple_common(Tuplesortstate *state, bool forward,
21242122LogicalTapeRewindForWrite (state -> tapeset ,srcTape );
21252123return true;
21262124}
2127- newtup .tupindex = srcTape ;
2125+ newtup .srctape = srcTape ;
21282126tuplesort_heap_replace_top (state ,& newtup );
21292127return true;
21302128}
@@ -2808,7 +2806,7 @@ mergeonerun(Tuplesortstate *state)
28082806SortTuple stup ;
28092807
28102808/* write the tuple to destTape */
2811- srcTape = state -> memtuples [0 ].tupindex ;
2809+ srcTape = state -> memtuples [0 ].srctape ;
28122810WRITETUP (state ,destTape ,& state -> memtuples [0 ]);
28132811
28142812/* recycle the slot of the tuple we just wrote out, for the next read */
@@ -2821,7 +2819,7 @@ mergeonerun(Tuplesortstate *state)
28212819 */
28222820if (mergereadnext (state ,srcTape ,& stup ))
28232821{
2824- stup .tupindex = srcTape ;
2822+ stup .srctape = srcTape ;
28252823tuplesort_heap_replace_top (state ,& stup );
28262824}
28272825else
@@ -2886,7 +2884,7 @@ beginmerge(Tuplesortstate *state)
28862884
28872885if (mergereadnext (state ,srcTape ,& tup ))
28882886{
2889- tup .tupindex = srcTape ;
2887+ tup .srctape = srcTape ;
28902888tuplesort_heap_insert (state ,& tup );
28912889}
28922890}