mirror of
https://github.com/postgres/postgres.git
synced 2025-04-24 10:47:04 +03:00
update comments
This commit is contained in:
Bruce Momjian
parent
02fa3e4394
commit
f3f7c2acde
@ -7,7 +7,7 @@
|
||||
*
|
||||
*
|
||||
* IDENTIFICATION
|
||||
* $Header: /cvsroot/pgsql/src/backend/executor/nodeMergejoin.c,v 1.23 1999/02/23 07:35:09 thomas Exp $
|
||||
* $Header: /cvsroot/pgsql/src/backend/executor/nodeMergejoin.c,v 1.24 1999/02/24 10:20:07 momjian Exp $
|
||||
*
|
||||
*-------------------------------------------------------------------------
|
||||
*/
|
||||
@ -288,7 +288,7 @@ MergeCompare(List *eqQual, List *compareQual, ExprContext *econtext)
|
||||
*/
|
||||
#ifdef EXEC_MERGEJOINDEBUG
|
||||
void
|
||||
ExecMergeTupleDumpInner(ExprContext *econtext);
|
||||
ExecMergeTupleDumpInner(ExprContext *econtext);
|
||||
|
||||
void
|
||||
ExecMergeTupleDumpInner(ExprContext *econtext)
|
||||
@ -305,7 +305,7 @@ ExecMergeTupleDumpInner(ExprContext *econtext)
|
||||
}
|
||||
|
||||
void
|
||||
ExecMergeTupleDumpOuter(ExprContext *econtext);
|
||||
ExecMergeTupleDumpOuter(ExprContext *econtext);
|
||||
|
||||
void
|
||||
ExecMergeTupleDumpOuter(ExprContext *econtext)
|
||||
@ -321,8 +321,7 @@ ExecMergeTupleDumpOuter(ExprContext *econtext)
|
||||
outerSlot->ttc_tupleDescriptor);
|
||||
}
|
||||
|
||||
void
|
||||
ExecMergeTupleDumpMarked(ExprContext *econtext,
|
||||
void ExecMergeTupleDumpMarked(ExprContext *econtext,
|
||||
MergeJoinState *mergestate);
|
||||
|
||||
void
|
||||
@ -342,7 +341,7 @@ ExecMergeTupleDumpMarked(ExprContext *econtext,
|
||||
}
|
||||
|
||||
void
|
||||
ExecMergeTupleDump(ExprContext *econtext, MergeJoinState *mergestate);
|
||||
ExecMergeTupleDump(ExprContext *econtext, MergeJoinState *mergestate);
|
||||
|
||||
void
|
||||
ExecMergeTupleDump(ExprContext *econtext, MergeJoinState *mergestate)
|
||||
@ -355,6 +354,7 @@ ExecMergeTupleDump(ExprContext *econtext, MergeJoinState *mergestate)
|
||||
|
||||
printf("******** \n");
|
||||
}
|
||||
|
||||
#endif
|
||||
|
||||
/* ----------------------------------------------------------------
|
||||
@ -427,11 +427,14 @@ ExecMergeJoin(MergeJoin *node)
|
||||
ExprContext *econtext;
|
||||
|
||||
#ifdef ENABLE_OUTER_JOINS
|
||||
/* These should be set from the expression context!
|
||||
* - thomas 1999-02-20
|
||||
|
||||
/*
|
||||
* These should be set from the expression context! - thomas
|
||||
* 1999-02-20
|
||||
*/
|
||||
static bool isLeftJoin = true;
|
||||
static bool isRightJoin = false;
|
||||
|
||||
#endif
|
||||
|
||||
/* ----------------
|
||||
@ -486,19 +489,19 @@ ExecMergeJoin(MergeJoin *node)
|
||||
switch (mergestate->mj_JoinState)
|
||||
{
|
||||
|
||||
/*********************************
|
||||
/*
|
||||
* EXEC_MJ_INITIALIZE means that this is the first time
|
||||
* ExecMergeJoin() has been called and so we have to initialize
|
||||
* the inner, outer and marked tuples as well as various stuff
|
||||
* in the expression context.
|
||||
*********************************/
|
||||
* ExecMergeJoin() has been called and so we have to
|
||||
* initialize the inner, outer and marked tuples as well
|
||||
* as various stuff in the expression context.
|
||||
*/
|
||||
case EXEC_MJ_INITIALIZE:
|
||||
MJ_printf("ExecMergeJoin: EXEC_MJ_INITIALIZE\n");
|
||||
/* ----------------
|
||||
|
||||
/*
|
||||
* Note: at this point, if either of our inner or outer
|
||||
* tuples are nil, then the join ends immediately because
|
||||
* we know one of the subplans is empty.
|
||||
* ----------------
|
||||
*/
|
||||
innerTupleSlot = ExecProcNode(innerPlan, (Plan *) node);
|
||||
if (TupIsNull(innerTupleSlot))
|
||||
@ -531,11 +534,12 @@ ExecMergeJoin(MergeJoin *node)
|
||||
mergestate->mj_JoinState = EXEC_MJ_SKIPINNER;
|
||||
break;
|
||||
|
||||
/*********************************
|
||||
* EXEC_MJ_JOINMARK means we have just found a new outer tuple
|
||||
* and a possible matching inner tuple. This is the case after
|
||||
* the INITIALIZE, SKIPOUTER or SKIPINNER states.
|
||||
*********************************/
|
||||
/*
|
||||
* EXEC_MJ_JOINMARK means we have just found a new outer
|
||||
* tuple and a possible matching inner tuple. This is the
|
||||
* case after the INITIALIZE, SKIPOUTER or SKIPINNER
|
||||
* states.
|
||||
*/
|
||||
case EXEC_MJ_JOINMARK:
|
||||
MJ_printf("ExecMergeJoin: EXEC_MJ_JOINMARK\n");
|
||||
ExecMarkPos(innerPlan);
|
||||
@ -545,7 +549,7 @@ ExecMergeJoin(MergeJoin *node)
|
||||
mergestate->mj_JoinState = EXEC_MJ_JOINTEST;
|
||||
break;
|
||||
|
||||
/*********************************
|
||||
/*
|
||||
* EXEC_MJ_JOINTEST means we have two tuples which might
|
||||
* satisfy the merge clause, so we test them.
|
||||
*
|
||||
@ -553,7 +557,7 @@ ExecMergeJoin(MergeJoin *node)
|
||||
* next inner tuple (EXEC_MJ_JOINTUPLES).
|
||||
*
|
||||
* If they do not satisfy then advance to next outer tuple.
|
||||
*********************************/
|
||||
*/
|
||||
case EXEC_MJ_JOINTEST:
|
||||
MJ_printf("ExecMergeJoin: EXEC_MJ_JOINTEST\n");
|
||||
|
||||
@ -566,11 +570,11 @@ ExecMergeJoin(MergeJoin *node)
|
||||
mergestate->mj_JoinState = EXEC_MJ_NEXTOUTER;
|
||||
break;
|
||||
|
||||
/*********************************
|
||||
/*
|
||||
* EXEC_MJ_JOINTUPLES means we have two tuples which
|
||||
* satisified the merge clause so we join them and then
|
||||
* proceed to get the next inner tuple (EXEC_NEXT_INNER).
|
||||
*********************************/
|
||||
*/
|
||||
case EXEC_MJ_JOINTUPLES:
|
||||
MJ_printf("ExecMergeJoin: EXEC_MJ_JOINTUPLES\n");
|
||||
mergestate->mj_JoinState = EXEC_MJ_NEXTINNER;
|
||||
@ -599,11 +603,11 @@ ExecMergeJoin(MergeJoin *node)
|
||||
}
|
||||
break;
|
||||
|
||||
/*********************************
|
||||
* EXEC_MJ_NEXTINNER means advance the inner scan to
|
||||
* the next tuple. If the tuple is not nil, we then
|
||||
* proceed to test it against the join qualification.
|
||||
*********************************/
|
||||
/*
|
||||
* EXEC_MJ_NEXTINNER means advance the inner scan to the
|
||||
* next tuple. If the tuple is not nil, we then proceed to
|
||||
* test it against the join qualification.
|
||||
*/
|
||||
case EXEC_MJ_NEXTINNER:
|
||||
MJ_printf("ExecMergeJoin: EXEC_MJ_NEXTINNER\n");
|
||||
|
||||
@ -621,7 +625,7 @@ ExecMergeJoin(MergeJoin *node)
|
||||
mergestate->mj_JoinState = EXEC_MJ_JOINTEST;
|
||||
break;
|
||||
|
||||
/*********************************
|
||||
/*-------------------------------------------
|
||||
* EXEC_MJ_NEXTOUTER means
|
||||
*
|
||||
* outer inner
|
||||
@ -635,7 +639,8 @@ ExecMergeJoin(MergeJoin *node)
|
||||
* so get a new outer tuple and then
|
||||
* proceed to test it against the marked tuple
|
||||
* (EXEC_MJ_TESTOUTER)
|
||||
*********************************/
|
||||
*------------------------------------------------
|
||||
*/
|
||||
case EXEC_MJ_NEXTOUTER:
|
||||
MJ_printf("ExecMergeJoin: EXEC_MJ_NEXTOUTER\n");
|
||||
|
||||
@ -657,7 +662,7 @@ ExecMergeJoin(MergeJoin *node)
|
||||
mergestate->mj_JoinState = EXEC_MJ_TESTOUTER;
|
||||
break;
|
||||
|
||||
/*********************************
|
||||
/*--------------------------------------------------------
|
||||
* EXEC_MJ_TESTOUTER If the new outer tuple and the marked
|
||||
* tuple satisfy the merge clause then we know we have
|
||||
* duplicates in the outer scan so we have to restore the
|
||||
@ -689,7 +694,8 @@ ExecMergeJoin(MergeJoin *node)
|
||||
*
|
||||
* new outer tuple > marked tuple
|
||||
*
|
||||
*********************************/
|
||||
*---------------------------------------------------------
|
||||
*/
|
||||
case EXEC_MJ_TESTOUTER:
|
||||
MJ_printf("ExecMergeJoin: EXEC_MJ_TESTOUTER\n");
|
||||
|
||||
@ -760,7 +766,7 @@ ExecMergeJoin(MergeJoin *node)
|
||||
}
|
||||
break;
|
||||
|
||||
/*********************************
|
||||
/*----------------------------------------------------------
|
||||
* EXEC_MJ_SKIPOUTER means skip over tuples in the outer plan
|
||||
* until we find an outer tuple > current inner tuple.
|
||||
*
|
||||
@ -775,7 +781,8 @@ ExecMergeJoin(MergeJoin *node)
|
||||
*
|
||||
* we have to advance the outer scan
|
||||
* until we find the outer 8.
|
||||
*********************************/
|
||||
*----------------------------------------------------------
|
||||
*/
|
||||
case EXEC_MJ_SKIPOUTER:
|
||||
MJ_printf("ExecMergeJoin: EXEC_MJ_SKIPOUTER\n");
|
||||
/* ----------------
|
||||
@ -867,7 +874,7 @@ ExecMergeJoin(MergeJoin *node)
|
||||
mergestate->mj_JoinState = EXEC_MJ_JOINMARK;
|
||||
break;
|
||||
|
||||
/*********************************
|
||||
/*-----------------------------------------------------------
|
||||
* EXEC_MJ_SKIPINNER means skip over tuples in the inner plan
|
||||
* until we find an inner tuple > current outer tuple.
|
||||
*
|
||||
@ -883,7 +890,8 @@ ExecMergeJoin(MergeJoin *node)
|
||||
* we have to advance the inner scan
|
||||
* until we find the inner 12.
|
||||
*
|
||||
*********************************/
|
||||
*-------------------------------------------------------
|
||||
*/
|
||||
case EXEC_MJ_SKIPINNER:
|
||||
MJ_printf("ExecMergeJoin: EXEC_MJ_SKIPINNER\n");
|
||||
/* ----------------
|
||||
@ -997,11 +1005,13 @@ ExecMergeJoin(MergeJoin *node)
|
||||
break;
|
||||
|
||||
#ifdef ENABLE_OUTER_JOINS
|
||||
/*********************************
|
||||
* EXEC_MJ_FILLINNER means we have an unmatched inner tuple
|
||||
* which must be null-expanded into the projection tuple.
|
||||
* get the next inner tuple and reset markers (EXEC_MJ_JOINMARK).
|
||||
*********************************/
|
||||
|
||||
/*
|
||||
* EXEC_MJ_FILLINNER means we have an unmatched inner
|
||||
* tuple which must be null-expanded into the projection
|
||||
* tuple. get the next inner tuple and reset markers
|
||||
* (EXEC_MJ_JOINMARK).
|
||||
*/
|
||||
case EXEC_MJ_FILLINNER:
|
||||
MJ_printf("ExecMergeJoin: EXEC_MJ_FILLINNER\n");
|
||||
mergestate->mj_JoinState = EXEC_MJ_JOINMARK;
|
||||
@ -1046,11 +1056,12 @@ ExecMergeJoin(MergeJoin *node)
|
||||
*/
|
||||
break;
|
||||
|
||||
/*********************************
|
||||
* EXEC_MJ_FILLOUTER means we have an unmatched outer tuple
|
||||
* which must be null-expanded into the projection tuple.
|
||||
* get the next outer tuple and reset markers (EXEC_MJ_JOINMARK).
|
||||
*********************************/
|
||||
/*
|
||||
* EXEC_MJ_FILLOUTER means we have an unmatched outer
|
||||
* tuple which must be null-expanded into the projection
|
||||
* tuple. get the next outer tuple and reset markers
|
||||
* (EXEC_MJ_JOINMARK).
|
||||
*/
|
||||
case EXEC_MJ_FILLOUTER:
|
||||
MJ_printf("ExecMergeJoin: EXEC_MJ_FILLOUTER\n");
|
||||
mergestate->mj_JoinState = EXEC_MJ_JOINMARK;
|
||||
@ -1095,10 +1106,10 @@ ExecMergeJoin(MergeJoin *node)
|
||||
break;
|
||||
#endif
|
||||
|
||||
/*********************************
|
||||
* if we get here it means our code is fouled up
|
||||
* and so we just end the join prematurely.
|
||||
*********************************/
|
||||
/*
|
||||
* if we get here it means our code is fouled up and so we
|
||||
* just end the join prematurely.
|
||||
*/
|
||||
default:
|
||||
elog(NOTICE, "ExecMergeJoin: invalid join state. aborting");
|
||||
return NULL;
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user