The interior of the RIGHT JOIN loop is now a subroutine.

FossilOrigin-Name: 549f5a7ee639de80f049445002f58e93c805f9a3d3db1987ec9d139ccef4805e

3 files changed, 46 insertions, 10 deletions

diff --git a/src/where.c b/src/where.c
index a5fab2cd5..afcecd77b 100644
--- a/src/where.c
+++ b/src/where.c
@@ -5869,12 +5869,18 @@ WhereInfo *sqlite3WhereBegin(
       }
     }
     if( iDb>=0 ) sqlite3CodeVerifySchema(pParse, iDb);
-    if( pTabItem->fg.jointype & JT_RIGHT ){
+    if( (pTabItem->fg.jointype & JT_RIGHT)!=0
+     && (pLevel->pRJ = sqlite3WhereMalloc(pWInfo, sizeof(WhereRightJoin)))!=0
+    ){
+      WhereRightJoin *pRJ = pLevel->pRJ;
+      pRJ->iMatch = pParse->nTab++;
+      pRJ->regBloom = ++pParse->nMem;
+      sqlite3VdbeAddOp2(v, OP_Blob, 65536, pRJ->regBloom);
+      pRJ->regReturn = ++pParse->nMem;
       assert( pTab==pTabItem->pTab );
-      pLevel->iRJMatch = pParse->nTab++;
       if( HasRowid(pTab) ){
         KeyInfo *pInfo;
-        sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pLevel->iRJMatch, 1);
+        sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pRJ->iMatch, 1);
         pInfo = sqlite3KeyInfoAlloc(pParse->db, 1, 0);
         if( pInfo ){
           pInfo->aColl[0] = 0;
@@ -5883,7 +5889,7 @@ WhereInfo *sqlite3WhereBegin(
         }
       }else{
         Index *pPk = sqlite3PrimaryKeyIndex(pTab);
-        sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pLevel->iRJMatch, pPk->nKeyCol);
+        sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pRJ->iMatch, pPk->nKeyCol);
         sqlite3VdbeSetP4KeyInfo(pParse, pPk);
       }
     }
@@ -5999,6 +6005,11 @@ void sqlite3WhereEnd(WhereInfo *pWInfo){
   for(i=pWInfo->nLevel-1; i>=0; i--){
     int addr;
     pLevel = &pWInfo->a[i];
+    if( pLevel->pRJ ){
+      WhereRightJoin *pRJ = (WhereRightJoin*)pLevel->pRJ;
+      sqlite3VdbeChangeP2(v, pRJ->addrSubrtn-1, sqlite3VdbeCurrentAddr(v));
+      sqlite3VdbeAddOp2(v, OP_Return, pRJ->regReturn, pRJ->addrSubrtn);
+    }
     pLoop = pLevel->pWLoop;
     if( pLevel->op!=OP_Noop ){
 #ifndef SQLITE_DISABLE_SKIPAHEAD_DISTINCT
diff --git a/src/whereInt.h b/src/whereInt.h
index df62db4f1..7b5be3011 100644
--- a/src/whereInt.h
+++ b/src/whereInt.h
@@ -33,6 +33,7 @@ typedef struct WhereScan WhereScan;
 typedef struct WhereOrCost WhereOrCost;
 typedef struct WhereOrSet WhereOrSet;
 typedef struct WhereMemBlock WhereMemBlock;
+typedef struct WhereRightJoin WhereRightJoin;
 
 /*
 ** This object is a header on a block of allocated memory that will be
@@ -44,6 +45,16 @@ struct WhereMemBlock {
 };
 
 /*
+** Extra information attached to a WhereLevel that is a RIGHT JOIN.
+*/
+struct WhereRightJoin {
+  int iMatch;          /* Cursor used to determine prior matched rows */
+  int regBloom;        /* Bloom filter for iRJMatch */
+  int regReturn;       /* Return register for the interior subroutine */
+  int addrSubrtn;      /* Starting address for the interior subroutine */
+};
+
+/*
 ** This object contains information needed to implement a single nested
 ** loop in WHERE clause.
 **
@@ -75,7 +86,7 @@ struct WhereLevel {
   int addrLikeRep;      /* LIKE range processing address */
 #endif
   int regFilter;        /* Bloom filter */
-  int iRJMatch;         /* Cursor or rowset used for matched RIGHT JOIN rows */
+  WhereRightJoin *pRJ;  /* Extra information for RIGHT JOIN */
   u8 iFrom;             /* Which entry in the FROM clause */
   u8 op, p3, p5;        /* Opcode, P3 & P5 of the opcode that ends the loop */
   int p1, p2;           /* Operands of the opcode used to end the loop */
diff --git a/src/wherecode.c b/src/wherecode.c
index 5b8ed8934..853646c71 100644
--- a/src/wherecode.c
+++ b/src/wherecode.c
@@ -2724,12 +2724,18 @@ Bitmask sqlite3WhereCodeOneLoopStart(
   /* For a RIGHT OUTER JOIN, record the fact that the current row has
   ** been matched at least once.
   */
-  if( pLevel->iRJMatch ){
+  if( pLevel->pRJ ){
     Table *pTab;
     int nPk;
     int r;
     int jmp1 = 0;
+    WhereRightJoin *pRJ = pLevel->pRJ;
 
+    /* pTab is the right-hand table of the RIGHT JOIN.  Generate code that
+    ** will record that the current row of that table has been matched at
+    ** least once.  This is accomplished by storing the PK for the row in
+    ** both the iMatch index and the regBloom Bloom filter.
+    */
     pTab = pWInfo->pTabList->a[pLevel->iFrom].pTab;
     if( HasRowid(pTab) ){
       r = sqlite3GetTempRange(pParse, 2);
@@ -2745,15 +2751,23 @@ Bitmask sqlite3WhereCodeOneLoopStart(
         sqlite3ExprCodeGetColumnOfTable(v, pTab, iCur, iCol,r+1+iPk);
       }
     }
-    jmp1 = sqlite3VdbeAddOp4Int(v, OP_Found, pLevel->iRJMatch, 0, r+1, nPk);
+    jmp1 = sqlite3VdbeAddOp4Int(v, OP_Found, pRJ->iMatch, 0, r+1, nPk);
     VdbeCoverage(v);
     sqlite3VdbeAddOp3(v, OP_MakeRecord, r+1, nPk, r);
-    sqlite3VdbeAddOp4Int(v, OP_IdxInsert, pLevel->iRJMatch, r, r+1, nPk);
+    sqlite3VdbeAddOp4Int(v, OP_IdxInsert, pRJ->iMatch, r, r+1, nPk);
+    sqlite3VdbeAddOp4Int(v, OP_FilterAdd, pRJ->regBloom, 0, r+1, nPk);
     sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
     sqlite3VdbeJumpHere(v, jmp1);
-
-    /* Release the array of temp registers */
     sqlite3ReleaseTempRange(pParse, r, nPk+1);
+
+    /* Create a subroutine used to process all interior loops and code
+    ** of the RIGHT JOIN.  During normal operation, the subroutine will
+    ** be in-line with the rest of the code.  But at the end, a separate
+    ** loop will run that invokes this subroutine for unmatched rows
+    ** of pTab, with all tables to left begin set to NULL.
+    */
+    sqlite3VdbeAddOp2(v, OP_BeginSubrtn, 0, pRJ->regReturn);
+    pRJ->addrSubrtn = sqlite3VdbeCurrentAddr(v);
   }
 
 #if WHERETRACE_ENABLED /* 0x20800 */