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‎src/backend/executor/nodeMergejoin.c

Lines changed: 89 additions & 78 deletions
Original file line numberDiff line numberDiff line change
@@ -7,7 +7,7 @@
77
*
88
*
99
* IDENTIFICATION
10-
* $Header: /cvsroot/pgsql/src/backend/executor/nodeMergejoin.c,v 1.23 1999/02/23 07:35:09 thomas Exp $
10+
* $Header: /cvsroot/pgsql/src/backend/executor/nodeMergejoin.c,v 1.24 1999/02/24 10:20:07 momjian Exp $
1111
*
1212
*-------------------------------------------------------------------------
1313
*/
@@ -288,7 +288,7 @@ MergeCompare(List *eqQual, List *compareQual, ExprContext *econtext)
288288
*/
289289
#ifdef EXEC_MERGEJOINDEBUG
290290
void
291-
ExecMergeTupleDumpInner(ExprContext *econtext);
291+
ExecMergeTupleDumpInner(ExprContext *econtext);
292292

293293
void
294294
ExecMergeTupleDumpInner(ExprContext *econtext)
@@ -305,7 +305,7 @@ ExecMergeTupleDumpInner(ExprContext *econtext)
305305
}
306306

307307
void
308-
ExecMergeTupleDumpOuter(ExprContext *econtext);
308+
ExecMergeTupleDumpOuter(ExprContext *econtext);
309309

310310
void
311311
ExecMergeTupleDumpOuter(ExprContext *econtext)
@@ -321,8 +321,7 @@ ExecMergeTupleDumpOuter(ExprContext *econtext)
321321
outerSlot->ttc_tupleDescriptor);
322322
}
323323

324-
void
325-
ExecMergeTupleDumpMarked(ExprContext *econtext,
324+
void ExecMergeTupleDumpMarked(ExprContext *econtext,
326325
MergeJoinState *mergestate);
327326

328327
void
@@ -342,7 +341,7 @@ ExecMergeTupleDumpMarked(ExprContext *econtext,
342341
}
343342

344343
void
345-
ExecMergeTupleDump(ExprContext *econtext, MergeJoinState *mergestate);
344+
ExecMergeTupleDump(ExprContext *econtext, MergeJoinState *mergestate);
346345

347346
void
348347
ExecMergeTupleDump(ExprContext *econtext, MergeJoinState *mergestate)
@@ -355,6 +354,7 @@ ExecMergeTupleDump(ExprContext *econtext, MergeJoinState *mergestate)
355354

356355
printf("******** \n");
357356
}
357+
358358
#endif
359359

360360
/* ----------------------------------------------------------------
@@ -427,11 +427,14 @@ ExecMergeJoin(MergeJoin *node)
427427
ExprContext *econtext;
428428

429429
#ifdef ENABLE_OUTER_JOINS
430-
/* These should be set from the expression context!
431-
* - thomas 1999-02-20
430+
431+
/*
432+
* These should be set from the expression context! - thomas
433+
* 1999-02-20
432434
*/
433435
static bool isLeftJoin = true;
434436
static bool isRightJoin = false;
437+
435438
#endif
436439

437440
/* ----------------
@@ -486,19 +489,19 @@ ExecMergeJoin(MergeJoin *node)
486489
switch (mergestate->mj_JoinState)
487490
{
488491

489-
/*********************************
492+
/*
490493
* EXEC_MJ_INITIALIZE means that this is the first time
491-
* ExecMergeJoin() has been called and so we have to initialize
492-
* the inner, outer and marked tuples as well as various stuff
493-
* in the expression context.
494-
*********************************/
494+
* ExecMergeJoin() has been called and so we have to
495+
* initialize the inner, outer and marked tuples as well
496+
* as various stuff in the expression context.
497+
*/
495498
case EXEC_MJ_INITIALIZE:
496499
MJ_printf("ExecMergeJoin: EXEC_MJ_INITIALIZE\n");
497-
/* ----------------
498-
* Note: at this point, if either of our inner or outer
499-
* tuples are nil, then the join ends immediately because
500-
* we know one of the subplans is empty.
501-
* ----------------
500+
501+
/*
502+
* Note: at this point, if either of our inner or outer
503+
* tuples are nil, then the join ends immediately because
504+
* we know one of the subplans is empty.
502505
*/
503506
innerTupleSlot = ExecProcNode(innerPlan, (Plan *) node);
504507
if (TupIsNull(innerTupleSlot))
@@ -531,11 +534,12 @@ ExecMergeJoin(MergeJoin *node)
531534
mergestate->mj_JoinState = EXEC_MJ_SKIPINNER;
532535
break;
533536

534-
/*********************************
535-
* EXEC_MJ_JOINMARK means we have just found a new outer tuple
536-
* and a possible matching inner tuple. This is the case after
537-
* the INITIALIZE, SKIPOUTER or SKIPINNER states.
538-
*********************************/
537+
/*
538+
* EXEC_MJ_JOINMARK means we have just found a new outer
539+
* tuple and a possible matching inner tuple. This is the
540+
* case after the INITIALIZE, SKIPOUTER or SKIPINNER
541+
* states.
542+
*/
539543
case EXEC_MJ_JOINMARK:
540544
MJ_printf("ExecMergeJoin: EXEC_MJ_JOINMARK\n");
541545
ExecMarkPos(innerPlan);
@@ -545,15 +549,15 @@ ExecMergeJoin(MergeJoin *node)
545549
mergestate->mj_JoinState = EXEC_MJ_JOINTEST;
546550
break;
547551

548-
/*********************************
552+
/*
549553
* EXEC_MJ_JOINTEST means we have two tuples which might
550554
* satisfy the merge clause, so we test them.
551555
*
552556
* If they do satisfy, then we join them and move on to the
553557
* next inner tuple (EXEC_MJ_JOINTUPLES).
554558
*
555559
* If they do not satisfy then advance to next outer tuple.
556-
*********************************/
560+
*/
557561
case EXEC_MJ_JOINTEST:
558562
MJ_printf("ExecMergeJoin: EXEC_MJ_JOINTEST\n");
559563

@@ -566,11 +570,11 @@ ExecMergeJoin(MergeJoin *node)
566570
mergestate->mj_JoinState = EXEC_MJ_NEXTOUTER;
567571
break;
568572

569-
/*********************************
573+
/*
570574
* EXEC_MJ_JOINTUPLES means we have two tuples which
571575
* satisified the merge clause so we join them and then
572576
* proceed to get the next inner tuple (EXEC_NEXT_INNER).
573-
*********************************/
577+
*/
574578
case EXEC_MJ_JOINTUPLES:
575579
MJ_printf("ExecMergeJoin: EXEC_MJ_JOINTUPLES\n");
576580
mergestate->mj_JoinState = EXEC_MJ_NEXTINNER;
@@ -599,11 +603,11 @@ ExecMergeJoin(MergeJoin *node)
599603
}
600604
break;
601605

602-
/*********************************
603-
* EXEC_MJ_NEXTINNER means advance the inner scan to
604-
* the next tuple. If the tuple is not nil, we then
605-
* proceed to test it against the join qualification.
606-
*********************************/
606+
/*
607+
* EXEC_MJ_NEXTINNER means advance the inner scan to the
608+
* next tuple. If the tuple is not nil, we then proceed to
609+
* test it against the join qualification.
610+
*/
607611
case EXEC_MJ_NEXTINNER:
608612
MJ_printf("ExecMergeJoin: EXEC_MJ_NEXTINNER\n");
609613

@@ -621,21 +625,22 @@ ExecMergeJoin(MergeJoin *node)
621625
mergestate->mj_JoinState = EXEC_MJ_JOINTEST;
622626
break;
623627

624-
/*********************************
628+
/*-------------------------------------------
625629
* EXEC_MJ_NEXTOUTER means
626630
*
627-
* outer inner
628-
* outer tuple - 5 5 - marked tuple
629-
* 5 5
630-
* 6 6 - inner tuple
631-
* 7 7
631+
* outer inner
632+
* outer tuple - 5 5 - marked tuple
633+
* 5 5
634+
* 6 6 - inner tuple
635+
* 7 7
632636
*
633-
* we know we just bumped into the
637+
* we know we just bumped into the
634638
* first inner tuple > current outer tuple
635639
* so get a new outer tuple and then
636640
* proceed to test it against the marked tuple
637641
* (EXEC_MJ_TESTOUTER)
638-
*********************************/
642+
*------------------------------------------------
643+
*/
639644
case EXEC_MJ_NEXTOUTER:
640645
MJ_printf("ExecMergeJoin: EXEC_MJ_NEXTOUTER\n");
641646

@@ -657,7 +662,7 @@ ExecMergeJoin(MergeJoin *node)
657662
mergestate->mj_JoinState = EXEC_MJ_TESTOUTER;
658663
break;
659664

660-
/*********************************
665+
/*--------------------------------------------------------
661666
* EXEC_MJ_TESTOUTER If the new outer tuple and the marked
662667
* tuple satisfy the merge clause then we know we have
663668
* duplicates in the outer scan so we have to restore the
@@ -687,9 +692,10 @@ ExecMergeJoin(MergeJoin *node)
687692
* 7 12
688693
*
689694
*
690-
* new outer tuple > marked tuple
695+
* new outer tuple > marked tuple
691696
*
692-
*********************************/
697+
*---------------------------------------------------------
698+
*/
693699
case EXEC_MJ_TESTOUTER:
694700
MJ_printf("ExecMergeJoin: EXEC_MJ_TESTOUTER\n");
695701

@@ -731,11 +737,11 @@ ExecMergeJoin(MergeJoin *node)
731737
* tuple didn't match the marked outer tuple then
732738
* we may have the case:
733739
*
734-
* outer inner
735-
* 4 4 - marked tuple
736-
* new outer - 5 4
737-
* 6 nil - inner tuple
738-
* 7
740+
* outer inner
741+
* 4 4 - marked tuple
742+
* new outer - 5 4
743+
* 6 nil - inner tuple
744+
* 7
739745
*
740746
* which means that all subsequent outer tuples will be
741747
* larger than our inner tuples.
@@ -760,22 +766,23 @@ ExecMergeJoin(MergeJoin *node)
760766
}
761767
break;
762768

763-
/*********************************
769+
/*----------------------------------------------------------
764770
* EXEC_MJ_SKIPOUTER means skip over tuples in the outer plan
765771
* until we find an outer tuple > current inner tuple.
766772
*
767773
* For example:
768774
*
769-
* outer inner
770-
* 5 5
771-
* 5 5
772-
* outer tuple - 6 8 - inner tuple
773-
* 7 12
774-
* 8 14
775+
* outer inner
776+
* 5 5
777+
* 5 5
778+
* outer tuple - 6 8 - inner tuple
779+
* 7 12
780+
* 8 14
775781
*
776782
* we have to advance the outer scan
777783
* until we find the outer 8.
778-
*********************************/
784+
*----------------------------------------------------------
785+
*/
779786
case EXEC_MJ_SKIPOUTER:
780787
MJ_printf("ExecMergeJoin: EXEC_MJ_SKIPOUTER\n");
781788
/* ----------------
@@ -867,23 +874,24 @@ ExecMergeJoin(MergeJoin *node)
867874
mergestate->mj_JoinState = EXEC_MJ_JOINMARK;
868875
break;
869876

870-
/*********************************
877+
/*-----------------------------------------------------------
871878
* EXEC_MJ_SKIPINNER means skip over tuples in the inner plan
872879
* until we find an inner tuple > current outer tuple.
873880
*
874881
* For example:
875882
*
876-
* outer inner
877-
* 5 5
878-
* 5 5
879-
* outer tuple - 12 8 - inner tuple
880-
* 14 10
881-
* 17 12
883+
* outer inner
884+
* 5 5
885+
* 5 5
886+
* outer tuple - 12 8 - inner tuple
887+
* 14 10
888+
* 17 12
882889
*
883890
* we have to advance the inner scan
884891
* until we find the inner 12.
885892
*
886-
*********************************/
893+
*-------------------------------------------------------
894+
*/
887895
case EXEC_MJ_SKIPINNER:
888896
MJ_printf("ExecMergeJoin: EXEC_MJ_SKIPINNER\n");
889897
/* ----------------
@@ -997,11 +1005,13 @@ ExecMergeJoin(MergeJoin *node)
9971005
break;
9981006

9991007
#ifdef ENABLE_OUTER_JOINS
1000-
/*********************************
1001-
* EXEC_MJ_FILLINNER means we have an unmatched inner tuple
1002-
* which must be null-expanded into the projection tuple.
1003-
* get the next inner tuple and reset markers (EXEC_MJ_JOINMARK).
1004-
*********************************/
1008+
1009+
/*
1010+
* EXEC_MJ_FILLINNER means we have an unmatched inner
1011+
* tuple which must be null-expanded into the projection
1012+
* tuple. get the next inner tuple and reset markers
1013+
* (EXEC_MJ_JOINMARK).
1014+
*/
10051015
case EXEC_MJ_FILLINNER:
10061016
MJ_printf("ExecMergeJoin: EXEC_MJ_FILLINNER\n");
10071017
mergestate->mj_JoinState = EXEC_MJ_JOINMARK;
@@ -1046,11 +1056,12 @@ ExecMergeJoin(MergeJoin *node)
10461056
*/
10471057
break;
10481058

1049-
/*********************************
1050-
* EXEC_MJ_FILLOUTER means we have an unmatched outer tuple
1051-
* which must be null-expanded into the projection tuple.
1052-
* get the next outer tuple and reset markers (EXEC_MJ_JOINMARK).
1053-
*********************************/
1059+
/*
1060+
* EXEC_MJ_FILLOUTER means we have an unmatched outer
1061+
* tuple which must be null-expanded into the projection
1062+
* tuple. get the next outer tuple and reset markers
1063+
* (EXEC_MJ_JOINMARK).
1064+
*/
10541065
case EXEC_MJ_FILLOUTER:
10551066
MJ_printf("ExecMergeJoin: EXEC_MJ_FILLOUTER\n");
10561067
mergestate->mj_JoinState = EXEC_MJ_JOINMARK;
@@ -1095,10 +1106,10 @@ ExecMergeJoin(MergeJoin *node)
10951106
break;
10961107
#endif
10971108

1098-
/*********************************
1099-
* if we get here it means our code is fouled up
1100-
* and so we just end the join prematurely.
1101-
*********************************/
1109+
/*
1110+
* if we get here it means our code is fouled up and so we
1111+
* just end the join prematurely.
1112+
*/
11021113
default:
11031114
elog(NOTICE, "ExecMergeJoin: invalid join state. aborting");
11041115
return NULL;

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