diff --git a/manifest b/manifest
index ede3df5706..2d7ec778f6 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Modify\sthe\squery\splanner\sinterface\sso\sthat\sit\salways\spasses\sin\sthe\sresult\sset.\nThis\sis\sthe\sfirst\sstep\stoward\sadding\san\soptimization\sthat\swill\somit\stables\nfrom\sa\sjoin\sthat\sdo\snot\scontribute\sto\sthe\sresult.
-D 2013-06-21T00:35:37.456
+C Attempt\sto\sdisable\sinner\sloops\sof\sa\sjoin\sthat\sdo\snot\sgenerate\soutput.\nThis\sdoes\snot\swork,\ssince\sthe\sinner\sloops\smight\srun\szero\stimes\sand\sthus\ninhibit\sall\soutput.\s\sNeeds\sto\sbe\senhanced\sto\swork\sonly\sfor\sLEFT\sJOINs\nor\swhen\swe\sknow\sthat\sthe\sinner\sloop\swill\salways\srun\sat\sleast\sonce.
+D 2013-06-21T02:05:06.206
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 5e41da95d92656a5004b03d3576e8b226858a28e
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -289,14 +289,14 @@ F src/vtab.c b05e5f1f4902461ba9f5fc49bb7eb7c3a0741a83
 F src/wal.c 436bfceb141b9423c45119e68e444358ee0ed35d
 F src/wal.h df01efe09c5cb8c8e391ff1715cca294f89668a4
 F src/walker.c 4fa43583d0a84b48f93b1e88f11adf2065be4e73
-F src/where.c c950b131584a40121092d735804472f567beefbc
+F src/where.c fc5293b54a70474c2b46e9df26c9e2803b152e68
 F test/8_3_names.test ebbb5cd36741350040fd28b432ceadf495be25b2
 F test/aggerror.test a867e273ef9e3d7919f03ef4f0e8c0d2767944f2
 F test/aggnested.test 45c0201e28045ad38a530b5a144b73cd4aa2cfd6
 F test/alias.test 4529fbc152f190268a15f9384a5651bbbabc9d87
 F test/all.test 6ff7b43c2b4b905c74dc4a813d201d0fa64c5783
 F test/alter.test 57d96ec9b320bd07af77567034488dcb6642c748
-F test/alter2.test 40531b1f89d4fe43f9007b1bfc304e291ed000ae
+F test/alter2.test 7ea05c7d92ac99349a802ef7ada17294dd647060
 F test/alter3.test 49c9d9fba2b8fcdce2dedeca97bbf1f369cc548d
 F test/alter4.test b2debc14d8cbe4c1d12ccd6a41eef88a8c1f15d5
 F test/altermalloc.test e81ac9657ed25c6c5bb09bebfa5a047cd8e4acfc
@@ -1096,10 +1096,7 @@ F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh fbc018d67fd7395f440c28f33ef0f94420226381
 F tool/wherecosttest.c f407dc4c79786982a475261866a161cd007947ae
 F tool/win/sqlite.vsix 97894c2790eda7b5bce3cc79cb2a8ec2fde9b3ac
-P 604c3c5de6fd8f8a569aa9ed981055a5b0123ba1
-R 54a7c9b08c105a408dfe2c4fd7fd4419
-T *branch * omit-join-table-opt
-T *sym-omit-join-table-opt *
-T -sym-nextgen-query-plan-exp *
+P 2c2577e69ccb47f1af674a755e71221e2ca0b322
+R b2263c66dd8a59884ee45351c335261a
 U drh
-Z d2a3072c8b463b513f8068b32a4cb830
+Z 6fd83e64fe937f64082b799e88969f81
diff --git a/manifest.uuid b/manifest.uuid
index 169f9d22e6..b8cca3c3d8 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-2c2577e69ccb47f1af674a755e71221e2ca0b322
\ No newline at end of file
+ca839723a21bb13d3e0666a672c15c6f3a267c2f
\ No newline at end of file
diff --git a/src/where.c b/src/where.c
index ab4170fe6f..18b4a3782e 100644
--- a/src/where.c
+++ b/src/where.c
@@ -392,10 +392,10 @@ struct WhereInfo {
   u8 okOnePass;             /* Ok to use one-pass algorithm for UPDATE/DELETE */
   u8 untestedTerms;         /* Not all WHERE terms resolved by outer loop */
   u8 eDistinct;             /* One of the WHERE_DISTINCT_* values below */
+  u8 nLevel;                /* Number of nested loop */
   int iTop;                 /* The very beginning of the WHERE loop */
   int iContinue;            /* Jump here to continue with next record */
   int iBreak;               /* Jump here to break out of the loop */
-  int nLevel;               /* Number of nested loop */
   int savedNQueryLoop;      /* pParse->nQueryLoop outside the WHERE loop */
   WhereMaskSet sMaskSet;    /* Map cursor numbers to bitmasks */
   WhereClause sWC;          /* Decomposition of the WHERE clause */
@@ -5370,8 +5370,9 @@ static int wherePathSolver(WhereInfo *pWInfo, WhereCost nRowEst){
     pLevel->iFrom = pWLoop->iTab;
     pLevel->iTabCur = pWInfo->pTabList->a[pLevel->iFrom].iCursor;
   }
-  if( (pWInfo->wctrlFlags & (WHERE_DISTINCTBY|WHERE_WANT_DISTINCT))
-                ==WHERE_WANT_DISTINCT
+  if( (pWInfo->wctrlFlags & WHERE_WANT_DISTINCT)!=0
+   && (pWInfo->wctrlFlags & WHERE_DISTINCTBY)==0
+   && pWInfo->eDistinct==WHERE_DISTINCT_NOOP
    && nRowEst
   ){
     Bitmask notUsed;
@@ -5571,15 +5572,23 @@ WhereInfo *sqlite3WhereBegin(
   WhereLoopBuilder sWLB;     /* The WhereLoop builder */
   WhereMaskSet *pMaskSet;    /* The expression mask set */
   WhereLevel *pLevel;        /* A single level in pWInfo->a[] */
+  WhereLoop *pLoop;          /* Pointer to a single WhereLoop object */
   int ii;                    /* Loop counter */
   sqlite3 *db;               /* Database connection */
   int rc;                    /* Return code */
 
 
   /* Variable initialization */
+  db = pParse->db;
   memset(&sWLB, 0, sizeof(sWLB));
   sWLB.pOrderBy = pOrderBy;
 
+  /* Disable the DISTINCT optimization if SQLITE_DistinctOpt is set via
+  ** sqlite3_test_ctrl(SQLITE_TESTCTRL_OPTIMIZATIONS,...) */
+  if( OptimizationDisabled(db, SQLITE_DistinctOpt) ){
+    wctrlFlags &= ~WHERE_WANT_DISTINCT;
+  }
+
   /* The number of tables in the FROM clause is limited by the number of
   ** bits in a Bitmask 
   */
@@ -5603,7 +5612,6 @@ WhereInfo *sqlite3WhereBegin(
   ** field (type Bitmask) it must be aligned on an 8-byte boundary on
   ** some architectures. Hence the ROUND8() below.
   */
-  db = pParse->db;
   nByteWInfo = ROUND8(sizeof(WhereInfo)+(nTabList-1)*sizeof(WhereLevel));
   pWInfo = sqlite3DbMallocZero(db, nByteWInfo + sizeof(WhereLoop));
   if( db->mallocFailed ){
@@ -5628,12 +5636,6 @@ WhereInfo *sqlite3WhereBegin(
   sWLB.pNew->cId = '*';
 #endif
 
-  /* Disable the DISTINCT optimization if SQLITE_DistinctOpt is set via
-  ** sqlite3_test_ctrl(SQLITE_TESTCTRL_OPTIMIZATIONS,...) */
-  if( OptimizationDisabled(db, SQLITE_DistinctOpt) ){
-    wctrlFlags &= ~WHERE_WANT_DISTINCT;
-  }
-
   /* Split the WHERE clause into separate subexpressions where each
   ** subexpression is separated by an AND operator.
   */
@@ -5718,7 +5720,6 @@ WhereInfo *sqlite3WhereBegin(
   if( wctrlFlags & WHERE_WANT_DISTINCT ){
     if( isDistinctRedundant(pParse, pTabList, &pWInfo->sWC, pResultSet) ){
       /* The DISTINCT marking is pointless.  Ignore it. */
-      wctrlFlags &= ~WHERE_WANT_DISTINCT;
       pWInfo->eDistinct = WHERE_DISTINCT_UNIQUE;
     }else if( pOrderBy==0 ){
       /* Try to ORDER BY the result set to make distinct processing easier */
@@ -5737,11 +5738,11 @@ WhereInfo *sqlite3WhereBegin(
 #ifdef WHERETRACE_ENABLED
     if( sqlite3WhereTrace ){
       WhereLoop *p;
-      int i = 0;
+      int i;
       static char zLabel[] = "0123456789abcdefghijklmnopqrstuvwyxz"
                                        "ABCDEFGHIJKLMNOPQRSTUVWYXZ";
-      for(p=pWInfo->pLoops; p; p=p->pNextLoop){
-        p->cId = zLabel[(i++)%sizeof(zLabel)];
+      for(p=pWInfo->pLoops, i=0; p; p=p->pNextLoop, i++){
+        p->cId = zLabel[i%sizeof(zLabel)];
         whereLoopPrint(p, pTabList);
       }
     }
@@ -5782,11 +5783,29 @@ WhereInfo *sqlite3WhereBegin(
       }
     }
     sqlite3DebugPrintf("\n");
-    for(ii=0; ii<nTabList; ii++){
+    for(ii=0; ii<pWInfo->nLevel; ii++){
       whereLoopPrint(pWInfo->a[ii].pWLoop, pTabList);
     }
   }
 #endif
+  /* Attempt to omit tables from the join that do not effect the result */
+  if( pResultSet!=0 && pWInfo->nLevel>=2 ){
+    Bitmask tabUsed = exprListTableUsage(pMaskSet, pResultSet);
+    if( pOrderBy ) tabUsed |= exprListTableUsage(pMaskSet, pOrderBy);
+    while( pWInfo->nLevel>=2 ){
+      pLoop = pWInfo->a[pWInfo->nLevel-1].pWLoop;
+      if( ((wctrlFlags & WHERE_WANT_DISTINCT)!=0
+           || (pLoop->wsFlags & WHERE_ONEROW)!=0)
+       && (tabUsed & pLoop->maskSelf)==0
+      ){
+        WHERETRACE(0xffff, ("-> drop loop %c not used\n", pLoop->cId));
+        pWInfo->nLevel--;
+        nTabList--;
+      }else{
+        break;
+      }
+    }
+  }
   WHERETRACE(0xffff,("*** Optimizer Finished ***\n"));
   pWInfo->pParse->nQueryLoop += pWInfo->nRowOut;
 
@@ -5955,7 +5974,7 @@ void sqlite3WhereEnd(WhereInfo *pWInfo){
 
   /* Close all of the cursors that were opened by sqlite3WhereBegin.
   */
-  assert( pWInfo->nLevel==1 || pWInfo->nLevel==pTabList->nSrc );
+  assert( pWInfo->nLevel<=pTabList->nSrc );
   for(i=0, pLevel=pWInfo->a; i<pWInfo->nLevel; i++, pLevel++){
     Index *pIdx = 0;
     struct SrcList_item *pTabItem = &pTabList->a[pLevel->iFrom];
diff --git a/test/alter2.test b/test/alter2.test
index db8a83bf9f..14be637f97 100644
--- a/test/alter2.test
+++ b/test/alter2.test
@@ -120,7 +120,6 @@ do_test alter2-1.5 {
   }
 } {}
 do_test alter2-1.6 {
-breakpoint
   execsql {
     SELECT c FROM abc ORDER BY c;
   }