Index: src/where.c
==================================================================
--- src/where.c
+++ src/where.c
@@ -2040,10 +2040,33 @@
      && p->rRun<=pTemplate->rRun                      /* (2b) */
      && p->nOut<=pTemplate->nOut                      /* (2c) */
     ){
       return 0;  /* Discard pTemplate */
     }
+
+    /* If pTemplate:
+    **
+    **   (1) uses the same index as existing where-loop p, 
+    **   (2) requires the same or a superset of tables to be scanned first, 
+    **   (3) constraints the same or fewer columns with ==, and
+    **   (4) skips more leading columns (skip-scan optimization).
+    **
+    ** the discard the template. This ensures that if stat4 data shows that:
+    **
+    **   WHERE (a=1 AND b=2)
+    **
+    ** is prohibitively expensive the planner does not instead do:
+    **
+    **   WHERE (ANY(a) AND b=2)
+    */
+    if( pTemplate->nSkip>p->nSkip                            /* (4) */
+     && pTemplate->u.btree.pIndex==p->u.btree.pIndex         /* (1) */
+     && pTemplate->u.btree.nEq<=p->u.btree.nEq               /* (3) */
+     && (pTemplate->prereq & p->prereq)==p->prereq           /* (2) */
+    ){
+      return 0;  /* Discard pTemplate */
+    }
 
     /* If pTemplate is always better than p, then cause p to be overwritten
     ** with pTemplate.  pTemplate is better than p if:
     **   (1)  pTemplate has no more dependences than p, and
     **   (2)  pTemplate has an equal or lower cost than p.

ADDED   test/analyzeG.test
Index: test/analyzeG.test
==================================================================
--- /dev/null
+++ test/analyzeG.test
@@ -0,0 +1,54 @@
+# 2018-07-04
+#
+# 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 analyzeG
+
+ifcapable {!stat4} {
+  finish_test
+  return
+}
+
+do_execsql_test 1.0 {
+  CREATE TABLE t1(a, b, c, d);
+  CREATE INDEX t1abc ON t1(a, b, c);
+  WITH s(i) AS (
+    SELECT 1 UNION ALL SELECT i+1 FROM s WHERE i<100000
+  )
+  INSERT INTO t1 SELECT 1,1,1,1 FROM s;
+
+  WITH s(i) AS (
+    SELECT 1 UNION ALL SELECT i+1 FROM s WHERE i<1000
+  )
+  INSERT INTO t1 SELECT i%5,i,i,i FROM s;
+}
+
+do_execsql_test 1.1 {
+  EXPLAIN QUERY PLAN SELECT * FROM t1 WHERE a=1 AND b=1 AND c>0
+} {
+  3 0 0 {SEARCH TABLE t1 USING INDEX t1abc (a=? AND b=? AND c>?)}
+}
+
+do_execsql_test 1.3 { 
+  ANALYZE 
+} {}
+
+do_execsql_test 1.4 {
+  EXPLAIN QUERY PLAN SELECT * FROM t1 WHERE a=1 AND b=1 AND c>0
+} {
+  2 0 0 {SCAN TABLE t1}
+}
+
+
+
+finish_test