diff --git a/manifest b/manifest
index a09f22df23..8c5d7d637c 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Adjust\sthe\smemory\susage\sbounds\son\sthe\smemsubsys1.test\sscript\sso\sthat\nit\sworks\son\samd64.\s(CVS\s5759)
-D 2008-10-01T13:55:51
+C Optimize\squeries\sthat\scontain\s"WHERE\srowid\sIN\s(x,\sy,\sz...)"\sby\susing\san\sintkey\sbtree\sto\sstore\sthe\s(x,\sy,\sz...)\sset\sinstead\sof\san\sindex\sbtree.\s(CVS\s5760)
+D 2008-10-02T13:50:56
 F Makefile.arm-wince-mingw32ce-gcc fcd5e9cd67fe88836360bb4f9ef4cb7f8e2fb5a0
 F Makefile.in e4ab842f9a64ef61d57093539a8aab76b12810db
 F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
@@ -107,7 +107,7 @@ F src/callback.c 7a40fd44da3eb89e7f6eff30aa6f940c45d73a97
 F src/complete.c cb14e06dbe79dee031031f0d9e686ff306afe07c
 F src/date.c 5c092296c03d658e84884121a694150964d6861d
 F src/delete.c bae6684aa02e1f7cf6328023157c91d9cf94200b
-F src/expr.c 04822d5c7af85fd195a5f72501ab5e8d99768fae
+F src/expr.c 61f5afca422f34194225cfd9bca9f2efd96c6179
 F src/fault.c dc88c821842157460750d2d61a8a8b4197d047ff
 F src/func.c 8431b40a7843d1024145684d303c55b4ee087bbe
 F src/global.c 20a3fe46c8287a01ba3a7442558f0eb70c66b19a
@@ -151,7 +151,7 @@ F src/select.c f118f8db2ce91a4cf972e6ae88c8e7cc8543f513
 F src/shell.c d83b578a8ccdd3e0e7fef4388a0887ce9f810967
 F src/sqlite.h.in 2be75cc1f2a5515db910e8d0e2d5954b493fd1f3
 F src/sqlite3ext.h 1e3887c9bd3ae66cb599e922824b04cd0d0f2c3e
-F src/sqliteInt.h dbe2797806c48f4a90adfea69dfbea95edd722ae
+F src/sqliteInt.h 437b408a7473293a903eb63f3c1d6ca814a13cdb
 F src/sqliteLimit.h f435e728c6b620ef7312814d660a81f9356eb5c8
 F src/status.c 237b193efae0cf6ac3f0817a208de6c6c6ef6d76
 F src/table.c 22744786199c9195720c15a7a42cb97b2e2728d8
@@ -362,6 +362,7 @@ F test/icu.test f51d0f4407ff8bb1e872f51a0e8b08fdc5a6897e
 F test/in.test d49419c6df515852f477fa513f3317181d46bc92
 F test/in2.test 5d4c61d17493c832f7d2d32bef785119e87bde75
 F test/in3.test 3cbf58c87f4052cee3a58b37b6389777505aa0c0
+F test/in4.test c043f75147295e9f6ad5040a5cda2c485736c2c8
 F test/incrblob.test e50cf41ac64e76ca4f8881ecb8d28fd988503ad5
 F test/incrblob2.test c82a780356bdf4d0c77f1adf0ea888248904fc07
 F test/incrblob_err.test c577c91d4ed9e8336cdb188b15d6ee2a6fe9604e
@@ -637,7 +638,7 @@ F tool/speedtest16.c c8a9c793df96db7e4933f0852abb7a03d48f2e81
 F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
 F tool/speedtest8.c 1dbced29de5f59ba2ebf877edcadf171540374d1
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
-P 59d2e89e2181c26b18eac68ccc80ea3018f70a5e
-R 2287b309c0341dad7ec54713b965b29d
-U drh
-Z d9d819f707dc5f486bedf318813a096b
+P aabde23fe19bd95371fdebdde66ac553dfd53f8e
+R 280f60e55a9bc8f499b588b678dbf711
+U danielk1977
+Z 0496772435641c7d88e45dbde24176e8
diff --git a/manifest.uuid b/manifest.uuid
index 0f29031168..7d1220adcb 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-aabde23fe19bd95371fdebdde66ac553dfd53f8e
\ No newline at end of file
+803a1736d56b3c07b8ad38715fe0e39196ecc507
\ No newline at end of file
diff --git a/src/expr.c b/src/expr.c
index ab0cf1e318..1925034dcf 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -12,7 +12,7 @@
 ** This file contains routines used for analyzing expressions and
 ** for generating VDBE code that evaluates expressions in SQLite.
 **
-** $Id: expr.c,v 1.394 2008/09/17 00:13:12 drh Exp $
+** $Id: expr.c,v 1.395 2008/10/02 13:50:56 danielk1977 Exp $
 */
 #include "sqliteInt.h"
 #include <ctype.h>
@@ -1214,11 +1214,13 @@ int sqlite3FindInIndex(Parse *pParse, Expr *pX, int *prNotFound){
 
   if( eType==0 ){
     int rMayHaveNull = 0;
+    eType = IN_INDEX_EPH;
     if( prNotFound ){
       *prNotFound = rMayHaveNull = ++pParse->nMem;
+    }else if( pX->pLeft->iColumn<0 && pX->pSelect==0 ){
+      eType = IN_INDEX_ROWID;
     }
-    sqlite3CodeSubselect(pParse, pX, rMayHaveNull);
-    eType = IN_INDEX_EPH;
+    sqlite3CodeSubselect(pParse, pX, rMayHaveNull, eType==IN_INDEX_ROWID);
   }else{
     pX->iTable = iTab;
   }
@@ -1237,9 +1239,20 @@ int sqlite3FindInIndex(Parse *pParse, Expr *pX, int *prNotFound){
 **
 ** The pExpr parameter describes the expression that contains the IN
 ** operator or subquery.
+**
+** If parameter isRowid is non-zero, then expression pExpr is guaranteed
+** to be of the form "<rowid> IN (?, ?, ?)", where <rowid> is a reference
+** to some integer key column of a table B-Tree. In this case, use an
+** intkey B-Tree to store the set of IN(...) values instead of the usual
+** (slower) variable length keys B-Tree.
 */
 #ifndef SQLITE_OMIT_SUBQUERY
-void sqlite3CodeSubselect(Parse *pParse, Expr *pExpr, int rMayHaveNull){
+void sqlite3CodeSubselect(
+  Parse *pParse, 
+  Expr *pExpr, 
+  int rMayHaveNull,
+  int isRowid
+){
   int testAddr = 0;                       /* One-time test address */
   Vdbe *v = sqlite3GetVdbe(pParse);
   if( v==0 ) return;
@@ -1267,12 +1280,13 @@ void sqlite3CodeSubselect(Parse *pParse, Expr *pExpr, int rMayHaveNull){
       char affinity;
       KeyInfo keyInfo;
       int addr;        /* Address of OP_OpenEphemeral instruction */
+      Expr *pLeft = pExpr->pLeft;
 
       if( rMayHaveNull ){
         sqlite3VdbeAddOp2(v, OP_Null, 0, rMayHaveNull);
       }
 
-      affinity = sqlite3ExprAffinity(pExpr->pLeft);
+      affinity = sqlite3ExprAffinity(pLeft);
 
       /* Whether this is an 'x IN(SELECT...)' or an 'x IN(<exprlist>)'
       ** expression it is handled the same way. A virtual table is 
@@ -1288,7 +1302,7 @@ void sqlite3CodeSubselect(Parse *pParse, Expr *pExpr, int rMayHaveNull){
       ** is used.
       */
       pExpr->iTable = pParse->nTab++;
-      addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pExpr->iTable, 1);
+      addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pExpr->iTable, !isRowid);
       memset(&keyInfo, 0, sizeof(keyInfo));
       keyInfo.nField = 1;
 
@@ -1301,6 +1315,7 @@ void sqlite3CodeSubselect(Parse *pParse, Expr *pExpr, int rMayHaveNull){
         SelectDest dest;
         ExprList *pEList;
 
+        assert( !isRowid );
         sqlite3SelectDestInit(&dest, SRT_Set, pExpr->iTable);
         dest.affinity = (int)affinity;
         assert( (pExpr->iTable&0x0000FFFF)==pExpr->iTable );
@@ -1351,14 +1366,23 @@ void sqlite3CodeSubselect(Parse *pParse, Expr *pExpr, int rMayHaveNull){
           r3 = sqlite3ExprCodeTarget(pParse, pE2, r1);
           assert( pParse->disableColCache>0 );
           pParse->disableColCache--;
-          sqlite3VdbeAddOp4(v, OP_MakeRecord, r3, 1, r2, &affinity, 1);
-          sqlite3ExprCacheAffinityChange(pParse, r3, 1);
-          sqlite3VdbeAddOp2(v, OP_IdxInsert, pExpr->iTable, r2);
+
+          if( isRowid ){
+            sqlite3VdbeAddOp2(v, OP_Null, 0, r2);
+            sqlite3VdbeAddOp2(v, OP_MustBeInt, r3, sqlite3VdbeCurrentAddr(v)+2);
+            sqlite3VdbeAddOp3(v, OP_Insert, pExpr->iTable, r2, r3);
+          }else{
+            sqlite3VdbeAddOp4(v, OP_MakeRecord, r3, 1, r2, &affinity, 1);
+            sqlite3ExprCacheAffinityChange(pParse, r3, 1);
+            sqlite3VdbeAddOp2(v, OP_IdxInsert, pExpr->iTable, r2);
+          }
         }
         sqlite3ReleaseTempReg(pParse, r1);
         sqlite3ReleaseTempReg(pParse, r2);
       }
-      sqlite3VdbeChangeP4(v, addr, (void *)&keyInfo, P4_KEYINFO);
+      if( !isRowid ){
+        sqlite3VdbeChangeP4(v, addr, (void *)&keyInfo, P4_KEYINFO);
+      }
       break;
     }
 
@@ -2026,7 +2050,7 @@ int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){
       testcase( op==TK_EXISTS );
       testcase( op==TK_SELECT );
       if( pExpr->iColumn==0 ){
-        sqlite3CodeSubselect(pParse, pExpr, 0);
+        sqlite3CodeSubselect(pParse, pExpr, 0, 0);
       }
       inReg = pExpr->iColumn;
       break;
@@ -2109,7 +2133,7 @@ int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){
           sqlite3VdbeJumpHere(v, j3);
 
           /* Copy the value of register rNotFound (which is either NULL or 0)
-	  ** into the target register. This will be the result of the
+          ** into the target register. This will be the result of the
           ** expression.
           */
           sqlite3VdbeAddOp2(v, OP_Copy, rNotFound, target);
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index af12e0f866..daa85a7224 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -11,7 +11,7 @@
 *************************************************************************
 ** Internal interface definitions for SQLite.
 **
-** @(#) $Id: sqliteInt.h,v 1.772 2008/09/12 16:03:48 drh Exp $
+** @(#) $Id: sqliteInt.h,v 1.773 2008/10/02 13:50:56 danielk1977 Exp $
 */
 #ifndef _SQLITEINT_H_
 #define _SQLITEINT_H_
@@ -2367,7 +2367,7 @@ void sqlite3AlterRenameTable(Parse*, SrcList*, Token*);
 int sqlite3GetToken(const unsigned char *, int *);
 void sqlite3NestedParse(Parse*, const char*, ...);
 void sqlite3ExpirePreparedStatements(sqlite3*);
-void sqlite3CodeSubselect(Parse *, Expr *, int);
+void sqlite3CodeSubselect(Parse *, Expr *, int, int);
 void sqlite3SelectPrep(Parse*, Select*, NameContext*);
 int sqlite3ResolveExprNames(NameContext*, Expr*);
 void sqlite3ResolveSelectNames(Parse*, Select*, NameContext*);
diff --git a/test/in4.test b/test/in4.test
new file mode 100644
index 0000000000..c13d8b1674
--- /dev/null
+++ b/test/in4.test
@@ -0,0 +1,93 @@
+# 2008 September 1
+#
+# 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.
+#
+#***********************************************************************
+#
+# $Id: in4.test,v 1.1 2008/10/02 13:50:56 danielk1977 Exp $
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+
+do_test in4-1.1 {
+  execsql {
+    CREATE TABLE t1(a, b);
+    CREATE INDEX i1 ON t1(a);
+  }
+} {}
+do_test in4-1.2 {
+  execsql {
+    SELECT * FROM t1 WHERE a IN ('aaa', 'bbb', 'ccc');
+  }
+} {}
+do_test in4-1.3 {
+  execsql {
+    INSERT INTO t1 VALUES('aaa', 1);
+    INSERT INTO t1 VALUES('ddd', 2);
+    INSERT INTO t1 VALUES('ccc', 3);
+    INSERT INTO t1 VALUES('eee', 4);
+    SELECT b FROM t1 WHERE a IN ('aaa', 'bbb', 'ccc');
+  }
+} {1 3}
+do_test in4-1.4 {
+  execsql {
+    SELECT a FROM t1 WHERE rowid IN (1, 3);
+  }
+} {aaa ccc}
+do_test in4-1.5 {
+  execsql {
+    SELECT a FROM t1 WHERE rowid IN ();
+  }
+} {}
+do_test in4-1.6 {
+  execsql {
+    SELECT a FROM t1 WHERE a IN ('ddd');
+  }
+} {ddd}
+
+do_test in4-2.1 {
+  execsql {
+    CREATE TABLE t2(a INTEGER PRIMARY KEY, b TEXT);
+    INSERT INTO t2 VALUES(-1, '-one');
+    INSERT INTO t2 VALUES(0, 'zero');
+    INSERT INTO t2 VALUES(1, 'one');
+    INSERT INTO t2 VALUES(2, 'two');
+    INSERT INTO t2 VALUES(3, 'three');
+  }
+} {}
+
+do_test in4-2.2 {
+  execsql { SELECT b FROM t2 WHERE a IN (0, 2) }
+} {zero two}
+
+do_test in4-2.3 {
+  execsql { SELECT b FROM t2 WHERE a IN (2, 0) }
+} {zero two}
+
+do_test in4-2.4 {
+  execsql { SELECT b FROM t2 WHERE a IN (2, -1) }
+} {-one two}
+
+do_test in4-2.5 {
+  execsql { SELECT b FROM t2 WHERE a IN (NULL, 3) }
+} {three}
+
+do_test in4-2.6 {
+  execsql { SELECT b FROM t2 WHERE a IN (1.0, 2.1) }
+} {one}
+
+do_test in4-2.7 {
+  execsql { SELECT b FROM t2 WHERE a IN ('1', '2') }
+} {one two}
+
+do_test in4-2.8 {
+  execsql { SELECT b FROM t2 WHERE a IN ('', '0.0.0', '2') }
+} {two}
+
+finish_test
+