diff --git a/manifest b/manifest
index 8c73ad3567..bf8f046722 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Add\snew\stest\sfile\scachespill.test.
-D 2017-04-26T17:21:33.779
+C Evaluate\sWHERE\sclause\sterms\sthat\sreference\sonly\sthe\sindex\sbefore\sevaluating\nterms\sthat\srequire\sthe\stable,\sand\sthereby\savoid\sseeking\sthe\stable\srow\sif\nindex\sterms\sare\sfalse.\nThis\sis\scalled\sthe\s"push-down"\soptimization\sin\sthe\sMySQL\sworld,\swe\sare\stold.
+D 2017-04-29T15:27:04.896
 F Makefile.in 1cc758ce3374a32425e4d130c2fe7b026b20de5b8843243de75f087c0a2661fb
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc 6a8c838220f7c00820e1fc0ac1bccaaa8e5676067e1dbfa1bafa7a4ffecf8ae6
@@ -485,7 +485,7 @@ F src/wal.h 06b2a0b599cc0f53ea97f497cf8c6b758c999f71
 F src/walker.c b71a992b413b3a022572eccf29ef4b4890223791
 F src/where.c c6352f15be5031907c68bcbde96cad1a6da20e9f4051d10168a59235de9a8566
 F src/whereInt.h 2a4b634d63ce488b46d4b0da8f2eaa8f9aeab202bc25ef76f007de5e3fba1f20
-F src/wherecode.c 943e32e9dccd0af802e0683ae11071c8bd808364e5908a5fb66758bd404c8681
+F src/wherecode.c 8ad48867660519e262a401720845dc76934f86f558ec9606335fafcd7a2554f8
 F src/whereexpr.c e913aaa7b73ffcce66abcea5f197e2c538d48b5df78d0b7bba8ff4d73cc2e745
 F test/8_3_names.test ebbb5cd36741350040fd28b432ceadf495be25b2
 F test/affinity2.test a6d901b436328bd67a79b41bb0ac2663918fe3bd
@@ -1043,6 +1043,7 @@ F test/printf.test b3ff34e73d59124140eaf89f7672e21bc2ca5fcc
 F test/printf2.test 9e6db85f81c63f2367c34a9d7db384088bd374ad
 F test/progress.test ebab27f670bd0d4eb9d20d49cef96e68141d92fb
 F test/ptrchng.test ef1aa72d6cf35a2bbd0869a649b744e9d84977fc
+F test/pushdown.test a5d2e5e66cc94cfb0989a5dd23e77427dd6c4313019155ba9051f52dfc5326aa
 F test/queryonly.test 5f653159e0f552f0552d43259890c1089391dcca
 F test/quick.test 1681febc928d686362d50057c642f77a02c62e57
 F test/quota-glob.test 32901e9eed6705d68ca3faee2a06b73b57cb3c26
@@ -1576,7 +1577,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 63d9ca5c7392e1efe3330689fe750310a952287e843b3242178724e8561fae0e
-R c4490df1c59aee5f8635e7285ee6a7e5
-U dan
-Z 2b0ae6051b3e0017c3cacc8dc5ffb6e4
+P 2d0b64316d66a362f5891ceb71a1fd8e4607732274b09b0a8472b97eef68ebc2 91dfb61a1a25763bb0b5c1e353a9d584bc6de3f6eb445f54202ffe7f6fee6e8d
+R d3fbd82e46a4092d676255e41f20df5b
+T +closed 91dfb61a1a25763bb0b5c1e353a9d584bc6de3f6eb445f54202ffe7f6fee6e8d
+U drh
+Z d8af2da2fe4450264227719b4f172b61
diff --git a/manifest.uuid b/manifest.uuid
index 44877c7f80..a192425962 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-2d0b64316d66a362f5891ceb71a1fd8e4607732274b09b0a8472b97eef68ebc2
\ No newline at end of file
+d7bb79ed3a40419d143fbe35c310e51fe7b384a22f082a61ad788671d2d33ee0
\ No newline at end of file
diff --git a/src/wherecode.c b/src/wherecode.c
index d429fbb523..feda45f911 100644
--- a/src/wherecode.c
+++ b/src/wherecode.c
@@ -1129,6 +1129,8 @@ Bitmask sqlite3WhereCodeOneLoopStart(
   int addrCont;                   /* Jump here to continue with next cycle */
   int iRowidReg = 0;        /* Rowid is stored in this register, if not zero */
   int iReleaseReg = 0;      /* Temp register to free before returning */
+  Index *pIdx = 0;          /* Index used by loop (if any) */
+  int loopAgain;            /* True if constraint generator loop should repeat */
 
   pParse = pWInfo->pParse;
   v = pParse->pVdbe;
@@ -1454,7 +1456,6 @@ Bitmask sqlite3WhereCodeOneLoopStart(
     int endEq;                   /* True if range end uses ==, >= or <= */
     int start_constraints;       /* Start of range is constrained */
     int nConstraint;             /* Number of constraint terms */
-    Index *pIdx;                 /* The index we will be using */
     int iIdxCur;                 /* The VDBE cursor for the index */
     int nExtraReg = 0;           /* Number of extra registers needed */
     int op;                      /* Instruction opcode */
@@ -1705,6 +1706,7 @@ Bitmask sqlite3WhereCodeOneLoopStart(
     }else{
       assert( pLevel->p5==0 );
     }
+    if( omitTable ) pIdx = 0;
   }else
 
 #ifndef SQLITE_OMIT_OR_OPTIMIZATION
@@ -2022,43 +2024,56 @@ Bitmask sqlite3WhereCodeOneLoopStart(
 
   /* Insert code to test every subexpression that can be completely
   ** computed using the current set of tables.
+  **
+  ** This loop may run either once (pIdx==0) or twice (pIdx!=0). If
+  ** it is run twice, then the first iteration codes those sub-expressions
+  ** that can be computed using columns from pIdx only (without seeking
+  ** the main table cursor). 
   */
-  for(pTerm=pWC->a, j=pWC->nTerm; j>0; j--, pTerm++){
-    Expr *pE;
-    int skipLikeAddr = 0;
-    testcase( pTerm->wtFlags & TERM_VIRTUAL );
-    testcase( pTerm->wtFlags & TERM_CODED );
-    if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
-    if( (pTerm->prereqAll & pLevel->notReady)!=0 ){
-      testcase( pWInfo->untestedTerms==0
-               && (pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE)!=0 );
-      pWInfo->untestedTerms = 1;
-      continue;
-    }
-    pE = pTerm->pExpr;
-    assert( pE!=0 );
-    if( pLevel->iLeftJoin && !ExprHasProperty(pE, EP_FromJoin) ){
-      continue;
-    }
-    if( pTerm->wtFlags & TERM_LIKECOND ){
-      /* If the TERM_LIKECOND flag is set, that means that the range search
-      ** is sufficient to guarantee that the LIKE operator is true, so we
-      ** can skip the call to the like(A,B) function.  But this only works
-      ** for strings.  So do not skip the call to the function on the pass
-      ** that compares BLOBs. */
+  do{
+    loopAgain = 0;
+    for(pTerm=pWC->a, j=pWC->nTerm; j>0; j--, pTerm++){
+      Expr *pE;
+      int skipLikeAddr = 0;
+      testcase( pTerm->wtFlags & TERM_VIRTUAL );
+      testcase( pTerm->wtFlags & TERM_CODED );
+      if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
+      if( (pTerm->prereqAll & pLevel->notReady)!=0 ){
+        testcase( pWInfo->untestedTerms==0
+            && (pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE)!=0 );
+        pWInfo->untestedTerms = 1;
+        continue;
+      }
+      pE = pTerm->pExpr;
+      assert( pE!=0 );
+      if( pLevel->iLeftJoin && !ExprHasProperty(pE, EP_FromJoin) ){
+        continue;
+      }
+      if( pIdx && !sqlite3ExprCoveredByIndex(pE, pLevel->iTabCur, pIdx) ){
+        loopAgain = 1;
+        continue;
+      }
+      if( pTerm->wtFlags & TERM_LIKECOND ){
+        /* If the TERM_LIKECOND flag is set, that means that the range search
+        ** is sufficient to guarantee that the LIKE operator is true, so we
+        ** can skip the call to the like(A,B) function.  But this only works
+        ** for strings.  So do not skip the call to the function on the pass
+        ** that compares BLOBs. */
 #ifdef SQLITE_LIKE_DOESNT_MATCH_BLOBS
-      continue;
+        continue;
 #else
-      u32 x = pLevel->iLikeRepCntr;
-      assert( x>0 );
-      skipLikeAddr = sqlite3VdbeAddOp1(v, (x&1)? OP_IfNot : OP_If, (int)(x>>1));
-      VdbeCoverage(v);
+        u32 x = pLevel->iLikeRepCntr;
+        assert( x>0 );
+        skipLikeAddr = sqlite3VdbeAddOp1(v, (x&1)?OP_IfNot:OP_If, (int)(x>>1));
+        VdbeCoverage(v);
 #endif
+      }
+      sqlite3ExprIfFalse(pParse, pE, addrCont, SQLITE_JUMPIFNULL);
+      if( skipLikeAddr ) sqlite3VdbeJumpHere(v, skipLikeAddr);
+      pTerm->wtFlags |= TERM_CODED;
     }
-    sqlite3ExprIfFalse(pParse, pE, addrCont, SQLITE_JUMPIFNULL);
-    if( skipLikeAddr ) sqlite3VdbeJumpHere(v, skipLikeAddr);
-    pTerm->wtFlags |= TERM_CODED;
-  }
+    pIdx = 0;
+  }while( loopAgain );
 
   /* Insert code to test for implied constraints based on transitivity
   ** of the "==" operator.
diff --git a/test/pushdown.test b/test/pushdown.test
new file mode 100644
index 0000000000..5be6054c08
--- /dev/null
+++ b/test/pushdown.test
@@ -0,0 +1,59 @@
+# 2017 April 29
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+set testprefix pushdown
+
+do_execsql_test 1.0 {
+  CREATE TABLE t1(a, b, c);
+  INSERT INTO t1 VALUES(1, 'b1', 'c1');
+  INSERT INTO t1 VALUES(2, 'b2', 'c2');
+  INSERT INTO t1 VALUES(3, 'b3', 'c3');
+  INSERT INTO t1 VALUES(4, 'b4', 'c4');
+  CREATE INDEX i1 ON t1(a, c);
+}
+
+proc f {val} {
+  lappend ::L $val
+  return 0
+}
+db func f f 
+
+do_test 1.1 {
+  set L [list]
+  execsql { SELECT * FROM t1 WHERE a=2 AND f(b) AND f(c) }
+  set L
+} {c2}
+
+do_test 1.2 {
+  set L [list]
+  execsql { SELECT * FROM t1 WHERE a=3 AND f(c) AND f(b) }
+  set L
+} {c3}
+
+do_execsql_test 1.3 {
+  DROP INDEX i1;
+  CREATE INDEX i1 ON t1(a, b);
+}
+do_test 1.4 {
+  set L [list]
+  execsql { SELECT * FROM t1 WHERE a=2 AND f(b) AND f(c) }
+  set L
+} {b2}
+
+do_test 1.5 {
+  set L [list]
+  execsql { SELECT * FROM t1 WHERE a=3 AND f(c) AND f(b) }
+  set L
+} {b3}
+  
+finish_test