Index: src/build.c
==================================================================
--- src/build.c
+++ src/build.c
@@ -3258,36 +3258,31 @@
 ** Apart from that, we have little to go on besides intuition as to
 ** how aiRowEst[] should be initialized.  The numbers generated here
 ** are based on typical values found in actual indices.
 */
 void sqlite3DefaultRowEst(Index *pIdx){
-#if 0
-  tRowcnt *a = pIdx->aiRowEst;
-  int i;
-  tRowcnt n;
-  assert( a!=0 );
-  a[0] = pIdx->pTable->nRowEst;
-  if( a[0]<10 ) a[0] = 10;
-  n = 10;
-  for(i=1; i<=pIdx->nKeyCol; i++){
-    a[i] = n;
-    if( n>5 ) n--;
-  }
-  if( pIdx->onError!=OE_None ){
-    a[pIdx->nKeyCol] = 1;
-  }
-#endif
-  /*            1000000, 10,  9,  8,  7,  6,  5,  4,  3,  2 */
-  LogEst aVal[] = { 33, 32, 30, 28, 26, 23, 20, 16, 10 };
+  /*                10,  9,  8,  7,  6 */
+  LogEst aVal[] = { 33, 32, 30, 28, 26 };
   LogEst *a = pIdx->aiRowLogEst;
   int nCopy = MIN(ArraySize(aVal), pIdx->nKeyCol);
+  int i;
 
+  /* Set the first entry (number of rows in the index) to the estimated 
+  ** number of rows in the table. Or 10, if the estimated number of rows 
+  ** in the table is less than that.  */
   a[0] = pIdx->pTable->nRowLogEst;
+  if( a[0]<33 ) a[0] = 33;        assert( 33==sqlite3LogEst(10) );
+
+  /* Estimate that a[1] is 10, a[2] is 9, a[3] is 8, a[4] is 7, a[5] is
+  ** 6 and each subsequent value (if any) is 5.  */
   memcpy(&a[1], aVal, nCopy*sizeof(LogEst));
-  if( pIdx->onError!=OE_None ){
-    a[pIdx->nKeyCol] = 0;
+  for(i=nCopy+1; i<=pIdx->nKeyCol; i++){
+    a[i] = 23;                    assert( 23==sqlite3LogEst(5) );
   }
+
+  assert( 0==sqlite3LogEst(1) );
+  if( pIdx->onError!=OE_None ) a[pIdx->nKeyCol] = 0;
 }
 
 /*
 ** This routine will drop an existing named index.  This routine
 ** implements the DROP INDEX statement.

Index: test/cost.test
==================================================================
--- test/cost.test
+++ test/cost.test
@@ -189,10 +189,55 @@
   0 0 2 {SCAN TABLE track} 
   0 1 0 {SEARCH TABLE album USING INTEGER PRIMARY KEY (rowid=?)}
   0 2 1 {SEARCH TABLE composer USING INTEGER PRIMARY KEY (rowid=?)}
   0 0 0 {USE TEMP B-TREE FOR DISTINCT}
 }
+
+#-------------------------------------------------------------------------
+#
+do_execsql_test 9.1 {
+  CREATE TABLE t1(
+    a,b,c,d,e, f,g,h,i,j,
+    k,l,m,n,o, p,q,r,s,t
+  );
+  CREATE INDEX i1 ON t1(k,l,m,n,o,p,q,r,s,t);
+}
+do_test 9.2 {
+  for {set i 0} {$i < 100} {incr i} {
+    execsql { INSERT INTO t1 DEFAULT VALUES }
+  }
+  execsql {
+    ANALYZE;
+    CREATE INDEX i2 ON t1(a,b,c,d,e,f,g,h,i,j);
+  }
+} {}
+
+set L [list a=? b=? c=? d=? e=? f=? g=? h=? i=? j=?]
+foreach {tn nTerm nRow} {
+  1   1 10
+  2   2  9
+  3   3  8
+  4   4  7
+  5   5  6
+  6   6  5
+  7   7  5
+  8   8  5
+  9   9  5
+  10 10  5
+} {
+  set w [join [lrange $L 0 [expr $nTerm-1]] " AND "]
+  set p1 [expr ($nRow-1) / 100.0]
+  set p2 [expr ($nRow+1) / 100.0]
+
+  set sql1 "SELECT * FROM t1 WHERE likelihood(k=?, $p1) AND $w"
+  set sql2 "SELECT * FROM t1 WHERE likelihood(k=?, $p2) AND $w"
+
+  do_eqp_test 9.3.$tn.1 $sql1 {/INDEX i1/}
+  do_eqp_test 9.3.$tn.2 $sql2 {/INDEX i2/}
+}
+
+
 
 finish_test