diff --git a/manifest b/manifest
index f4c15b028c..ebe09dacca 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Silence\sa\sharmless\sunitialised\svariable\swarning\sin\sbtree.c.\sTicket\s#2862.\s(CVS\s4650)
-D 2008-01-01T06:19:02
+C Optimize\strigger\scompilation\sto\savoid\spopulating\sthe\sOLD.*\sand\sNEW.*\spseudo-tables\swith\sdata\sthat\swill\snever\sbe\sused.\sSome\stesting\sto\scome.\s(CVS\s4651)
+D 2008-01-01T19:02:09
 F Makefile.arm-wince-mingw32ce-gcc ac5f7b2cef0cd850d6f755ba6ee4ab961b1fadf7
 F Makefile.in 30789bf70614bad659351660d76b8e533f3340e9
 F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
@@ -90,13 +90,13 @@ F src/build.c cbfd98ceb95c61c226cd60a845fa7967b66c8931
 F src/callback.c 77b302b0d41468dcda78c70e706e5b84577f0fa0
 F src/complete.c 4cf68fd75d60257524cbe74f87351b9848399131
 F src/date.c 49c5a6d2de6c12000905b4d36868b07d3011bbf6
-F src/delete.c 1f957c4acb2270772c6fab8411459e7dd43d585f
+F src/delete.c 6c090aeb5e97a224ee1f232a02359ee79e8ab411
 F src/experimental.c 1b2d1a6cd62ecc39610e97670332ca073c50792b
-F src/expr.c 43807e139e14957330095d9ac183f7ad449ce907
+F src/expr.c d0969aa79a8e12f8ba49ffe97ae671bee47e37dc
 F src/func.c 996071cf0af9d967e58b69fce1909555059ebc7d
 F src/hash.c 45a7005aac044b6c86bd7e49c44bc15d30006d6c
 F src/hash.h 031cd9f915aff27e12262cb9eb570ac1b8326b53
-F src/insert.c 2b145fca8e538b7f2c2de429e931c1501e55e5ac
+F src/insert.c 3c82c974150506bed75f58dec3744503bf112dd4
 F src/journal.c 807bed7a158979ac8d63953e1774e8d85bff65e2
 F src/legacy.c 4ac53191fad2e3c4d59bde1228879b2dc5a96d66
 F src/limits.h 71ab25f17e35e0a9f3f6f234b8ed49cc56731d35
@@ -131,12 +131,12 @@ F src/pragma.c dd5b1983168eacba1a5084571775b904ea95404f
 F src/prepare.c 7aeba7851773fbe3950a26b35d3389bef0eb1c62
 F src/printf.c eb27822ba2eec669161409ca31279a24c26ac910
 F src/random.c 4a22746501bf36b0a088c66e38dde5daba6a35da
-F src/select.c 5a137027415a74e950603baddbbcbe9d3f8bc5a5
+F src/select.c 247d668f5be042b914ed8e46edf9cdb57a1eca29
 F src/server.c 087b92a39d883e3fa113cae259d64e4c7438bc96
 F src/shell.c 77895a54c2082157e169c857a2e244525ec25af7
 F src/sqlite.h.in 2a7e3776534bbe6ff2cdc058f3abebe91e7e429f
 F src/sqlite3ext.h a93f59cdee3638dc0c9c086f80df743a4e68c3cb
-F src/sqliteInt.h 445530263725d19d6315f137f234aea08ad59303
+F src/sqliteInt.h cf993fe510f6a4cdc18e60b80eee3725c2f1001e
 F src/sqliteLimit.h ee4430f88f69bf63527967bb35ca52af7b0ccb1e
 F src/table.c 1aeb9eab57b4235db86fe15a35dec76fb445a9c4
 F src/tclsqlite.c 9923abeffc9b3d7dad58e92b319661521f60debf
@@ -163,8 +163,8 @@ F src/test_server.c a6ece6c835e7eae835054124e09e947e422b1ac5
 F src/test_tclvar.c b2d1115e4d489179d3f029e765211b2ad527ba59
 F src/test_thread.c e297dd41db0b249646e69f97d36ec13e56e8b730
 F src/tokenize.c a4e04438c11fed2c67ec47fe3edbef9cca2d1b48
-F src/trigger.c 66695e1375b969ea41a38dec9f40ea28bb0ac767
-F src/update.c 57c07b63410cdd3d14888e33439aa1955a3514c1
+F src/trigger.c 24bdfee77ce9472db91267597225506c31fc3d9b
+F src/update.c 59124a9d5d52bb411f6fba6475b93f2f443fc971
 F src/utf.c ef4b7d83bae533b76c3e1bf635b113fdad86a736
 F src/util.c 05f31144bbd3f1a24f4139ae029c42545cb72624
 F src/vacuum.c 25ffbd766f25bca099ead1c1e11f5528c86102b8
@@ -193,7 +193,7 @@ F test/attach.test 72529edb04115675894a7399609983ea46b73ba6
 F test/attach2.test a295d2d7061adcee5884ef4a93c7c96a82765437
 F test/attach3.test 7b92dc8e40c1ebca9732ca6f2d3fefbd46f196df
 F test/attachmalloc.test 56c5e55563dba6d64641ef2f70ce06900df16912
-F test/auth.test 74b49b669cb6ca022124838ff957e1e11b1a8002
+F test/auth.test be181f70ced0c84ecb5e2515d9b620f89f6a7b87
 F test/auth2.test 65ac294b8d52cbdd463f61e77ad0165268373126
 F test/autoinc.test 0e67964f4855081e3a325e484adfebaab41f23a1
 F test/autovacuum.test 4339e66003b9cf813dd667a83aed2dee27c4c36d
@@ -493,6 +493,7 @@ F test/trigger5.test 619391a3e9fc194081d22cefd830d811e7badf83
 F test/trigger6.test 0e411654f122552da6590f0b4e6f781048a4a9b9
 F test/trigger7.test 0afa870be2ce1b132cdb85b17a4a4ef45aa8cece
 F test/trigger8.test 3a09275aa2214fdff56f731b1e775d8dfee4408a
+F test/trigger9.test 49c7cb761e9d3617ed868717b90b545e9bae8e73
 F test/types.test 98e7a631bddf0806204358b452b02d0e319318a6
 F test/types2.test 3555aacf8ed8dc883356e59efc314707e6247a84
 F test/types3.test b730a7db03ef69f0fdb85b2addc20d1a0a04039b
@@ -602,7 +603,7 @@ F www/tclsqlite.tcl 8be95ee6dba05eabcd27a9d91331c803f2ce2130
 F www/vdbe.tcl 87a31ace769f20d3627a64fa1fade7fed47b90d0
 F www/version3.tcl 890248cf7b70e60c383b0e84d77d5132b3ead42b
 F www/whentouse.tcl fc46eae081251c3c181bd79c5faef8195d7991a5
-P 6dea8c16384443ed4ab59d1e2694534992ec3118
-R 782ae7c60f2ef919b3a8af5b140614e6
+P b51782ccac28598eec7adc9302fe7d1986bfdaf8
+R 904ead844e1f41e01a54c3518029f00d
 U danielk1977
-Z 52c90bef75d1e50f96fdd91d4d73d155
+Z 755babd79b5a2ad03f400826316421af
diff --git a/manifest.uuid b/manifest.uuid
index 02ebc8d64a..8c20d9c76c 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-b51782ccac28598eec7adc9302fe7d1986bfdaf8
\ No newline at end of file
+e08a33ed7255c22ce2805363f44a1d7770acb2dd
\ No newline at end of file
diff --git a/src/delete.c b/src/delete.c
index 10c6cffa44..77a2c6d822 100644
--- a/src/delete.c
+++ b/src/delete.c
@@ -12,7 +12,7 @@
 ** This file contains C code routines that are called by the parser
 ** in order to generate code for DELETE FROM statements.
 **
-** $Id: delete.c,v 1.134 2007/12/12 17:42:53 danielk1977 Exp $
+** $Id: delete.c,v 1.135 2008/01/01 19:02:09 danielk1977 Exp $
 */
 #include "sqliteInt.h"
 
@@ -113,6 +113,11 @@ void sqlite3DeleteFrom(
   int isView;                  /* True if attempting to delete from a view */
   int triggers_exist = 0;      /* True if any triggers exist */
 #endif
+  int iBeginAfterTrigger;      /* Address of after trigger program */
+  int iEndAfterTrigger;        /* Exit of after trigger program */
+  int iBeginBeforeTrigger;     /* Address of before trigger program */
+  int iEndBeforeTrigger;       /* Exit of before trigger program */
+  u32 old_col_mask = 0;        /* Mask of OLD.* columns in use */
 
   sContext.pParse = 0;
   db = pParse->db;
@@ -192,11 +197,28 @@ void sqlite3DeleteFrom(
   if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);
   sqlite3BeginWriteOperation(pParse, triggers_exist, iDb);
 
+  if( triggers_exist ){
+    int iGoto = sqlite3VdbeAddOp(v, OP_Goto, 0, 0);
+    addr = sqlite3VdbeMakeLabel(v);
+    iBeginBeforeTrigger = sqlite3VdbeCurrentAddr(v);
+    (void)sqlite3CodeRowTrigger(pParse, TK_DELETE, 0, TRIGGER_BEFORE, pTab,
+        -1, oldIdx, (pParse->trigStack)?pParse->trigStack->orconf:OE_Default,
+        addr, &old_col_mask, 0);
+    iEndBeforeTrigger = sqlite3VdbeAddOp(v, OP_Goto, 0, 0);
+    iBeginAfterTrigger = sqlite3VdbeCurrentAddr(v);
+    (void)sqlite3CodeRowTrigger(pParse, TK_DELETE, 0, TRIGGER_AFTER, pTab, -1,
+        oldIdx, (pParse->trigStack)?pParse->trigStack->orconf:OE_Default,
+        addr, &old_col_mask, 0);
+    iEndAfterTrigger = sqlite3VdbeAddOp(v, OP_Goto, 0, 0);
+    sqlite3VdbeJumpHere(v, iGoto);
+  }
+
   /* If we are trying to delete from a view, realize that view into
   ** a ephemeral table.
   */
   if( isView ){
     Select *pView = sqlite3SelectDup(db, pTab->pSelect);
+    sqlite3SelectMask(pParse, pView, old_col_mask);
     sqlite3Select(pParse, pView, SRT_EphemTab, iCur, 0, 0, 0, 0);
     sqlite3SelectDelete(pView);
   }
@@ -276,6 +298,9 @@ void sqlite3DeleteFrom(
     */
     if( triggers_exist ){
       int mem1 = pParse->nMem++;
+      int addr_rowdata;
+      u32 mask;
+      sqlite3VdbeResolveLabel(v, addr);
       addr = sqlite3VdbeAddOp(v, OP_FifoRead, 0, end);
       sqlite3VdbeAddOp(v, OP_StackDepth, -1, 0);
       sqlite3VdbeAddOp(v, OP_MemStore, mem1, 0);
@@ -284,15 +309,20 @@ void sqlite3DeleteFrom(
       }
       sqlite3VdbeAddOp(v, OP_NotExists, iCur, addr);
       sqlite3VdbeAddOp(v, OP_Rowid, iCur, 0);
-      sqlite3VdbeAddOp(v, OP_RowData, iCur, 0);
+      if( old_col_mask ){
+        sqlite3VdbeAddOp(v, OP_RowData, iCur, 0);
+      }else{
+        sqlite3VdbeAddOp(v, OP_Null, 0, 0);
+      }
       sqlite3VdbeAddOp(v, OP_Insert, oldIdx, 0);
       if( !isView ){
         sqlite3VdbeAddOp(v, OP_Close, iCur, 0);
       }
 
-      (void)sqlite3CodeRowTrigger(pParse, TK_DELETE, 0, TRIGGER_BEFORE, pTab,
-          -1, oldIdx, (pParse->trigStack)?pParse->trigStack->orconf:OE_Default,
-          addr);
+      /* Jump back and run the BEFORE triggers */
+      sqlite3VdbeAddOp(v, OP_Goto, 0, iBeginBeforeTrigger);
+      sqlite3VdbeJumpHere(v, iEndBeforeTrigger);
+
       if( !isView ){
         sqlite3VdbeAddOp(v, OP_MemLoad, mem1, 0);
       }
@@ -336,9 +366,10 @@ void sqlite3DeleteFrom(
         }
         sqlite3VdbeAddOp(v, OP_Close, iCur, 0);
       }
-      (void)sqlite3CodeRowTrigger(pParse, TK_DELETE, 0, TRIGGER_AFTER, pTab, -1,
-          oldIdx, (pParse->trigStack)?pParse->trigStack->orconf:OE_Default,
-          addr);
+
+      /* Jump back and run the AFTER triggers */
+      sqlite3VdbeAddOp(v, OP_Goto, 0, iBeginAfterTrigger);
+      sqlite3VdbeJumpHere(v, iEndAfterTrigger);
     }
 
     /* End of the delete loop */
diff --git a/src/expr.c b/src/expr.c
index 214193ca10..7fd53ae6c7 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 1.320 2007/12/14 15:12:21 drh Exp $
+** $Id: expr.c,v 1.321 2008/01/01 19:02:09 danielk1977 Exp $
 */
 #include "sqliteInt.h"
 #include <ctype.h>
@@ -1107,14 +1107,17 @@ static int lookupName(
     if( zDb==0 && zTab!=0 && cnt==0 && pParse->trigStack!=0 ){
       TriggerStack *pTriggerStack = pParse->trigStack;
       Table *pTab = 0;
+      u32 *piColMask;
       if( pTriggerStack->newIdx != -1 && sqlite3StrICmp("new", zTab) == 0 ){
         pExpr->iTable = pTriggerStack->newIdx;
         assert( pTriggerStack->pTab );
         pTab = pTriggerStack->pTab;
+        piColMask = &(pTriggerStack->newColMask);
       }else if( pTriggerStack->oldIdx != -1 && sqlite3StrICmp("old", zTab)==0 ){
         pExpr->iTable = pTriggerStack->oldIdx;
         assert( pTriggerStack->pTab );
         pTab = pTriggerStack->pTab;
+        piColMask = &(pTriggerStack->oldColMask);
       }
 
       if( pTab ){ 
@@ -1133,6 +1136,9 @@ static int lookupName(
               pExpr->pColl = sqlite3FindCollSeq(db, ENC(db), zColl,-1, 0);
             }
             pExpr->pTab = pTab;
+            if( iCol>=0 ){
+              *piColMask |= ((u32)1<<iCol) | (iCol>=32?0xffffffff:0);
+            }
             break;
           }
         }
diff --git a/src/insert.c b/src/insert.c
index 3720af60ea..7f72e95d44 100644
--- a/src/insert.c
+++ b/src/insert.c
@@ -12,7 +12,7 @@
 ** This file contains C code routines that are called by the parser
 ** to handle INSERT statements in SQLite.
 **
-** $Id: insert.c,v 1.197 2007/12/14 16:11:09 drh Exp $
+** $Id: insert.c,v 1.198 2008/01/01 19:02:09 danielk1977 Exp $
 */
 #include "sqliteInt.h"
 
@@ -708,7 +708,7 @@ void sqlite3Insert(
 
     /* Fire BEFORE or INSTEAD OF triggers */
     if( sqlite3CodeRowTrigger(pParse, TK_INSERT, 0, TRIGGER_BEFORE, pTab, 
-        newIdx, -1, onError, endOfLoop) ){
+        newIdx, -1, onError, endOfLoop, 0, 0) ){
       goto insert_cleanup;
     }
   }
@@ -837,7 +837,7 @@ void sqlite3Insert(
 
     /* Code AFTER triggers */
     if( sqlite3CodeRowTrigger(pParse, TK_INSERT, 0, TRIGGER_AFTER, pTab,
-          newIdx, -1, onError, endOfLoop) ){
+          newIdx, -1, onError, endOfLoop, 0, 0) ){
       goto insert_cleanup;
     }
   }
diff --git a/src/select.c b/src/select.c
index 605a74405d..142244c0dd 100644
--- a/src/select.c
+++ b/src/select.c
@@ -12,7 +12,7 @@
 ** This file contains C code routines that are called by the parser
 ** to handle SELECT statements in SQLite.
 **
-** $Id: select.c,v 1.372 2007/12/14 17:24:40 drh Exp $
+** $Id: select.c,v 1.373 2008/01/01 19:02:09 danielk1977 Exp $
 */
 #include "sqliteInt.h"
 
@@ -2961,6 +2961,35 @@ static void updateAccumulator(Parse *pParse, AggInfo *pAggInfo){
   pAggInfo->directMode = 0;
 }
 
+#ifndef SQLITE_OMIT_TRIGGER
+/*
+** This function is used when a SELECT statement is used to create a
+** temporary table for iterating through when running an INSTEAD OF
+** UPDATE or INSTEAD OF DELETE trigger. 
+**
+** If possible, the SELECT statement is modified so that NULL values
+** are stored in the temporary table for all columns for which the 
+** corresponding bit in argument mask is not set. If mask takes the
+** special value 0xffffffff, then all columns are populated.
+*/
+int sqlite3SelectMask(Parse *pParse, Select *p, u32 mask){
+  if( !p->pPrior && !p->isDistinct && mask!=0xffffffff ){
+    ExprList *pEList;
+    int i;
+    if( sqlite3SelectResolve(pParse, p, 0) ){
+      return SQLITE_ERROR;
+    }
+    pEList = p->pEList;
+    for(i=0; i<pEList->nExpr && i<32; i++){
+      if( !(mask&((u32)1<<i)) ){
+        sqlite3ExprDelete(pEList->a[i].pExpr);
+        pEList->a[i].pExpr = sqlite3Expr(pParse->db, TK_NULL, 0, 0, 0);
+      }
+    }
+  }
+  return SQLITE_OK;
+}
+#endif
 
 /*
 ** Generate code for the given SELECT statement.
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 825ca21e2b..a59ec170f6 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -11,7 +11,7 @@
 *************************************************************************
 ** Internal interface definitions for SQLite.
 **
-** @(#) $Id: sqliteInt.h,v 1.626 2007/12/13 03:45:08 drh Exp $
+** @(#) $Id: sqliteInt.h,v 1.627 2008/01/01 19:02:09 danielk1977 Exp $
 */
 #ifndef _SQLITEINT_H_
 #define _SQLITEINT_H_
@@ -1558,6 +1558,8 @@ struct TriggerStack {
   Table *pTab;         /* Table that triggers are currently being coded on */
   int newIdx;          /* Index of vdbe cursor to "new" temp table */
   int oldIdx;          /* Index of vdbe cursor to "old" temp table */
+  u32 newColMask;
+  u32 oldColMask;
   int orconf;          /* Current orconf policy */
   int ignoreJump;      /* where to jump to for a RAISE(IGNORE) */
   Trigger *pTrigger;   /* The trigger currently being coded */
@@ -1716,6 +1718,7 @@ int sqlite3Select(Parse*, Select*, int, int, Select*, int, int*, char *aff);
 Select *sqlite3SelectNew(Parse*,ExprList*,SrcList*,Expr*,ExprList*,
                          Expr*,ExprList*,int,Expr*,Expr*);
 void sqlite3SelectDelete(Select*);
+int sqlite3SelectMask(Parse *, Select *, u32);
 Table *sqlite3SrcListLookup(Parse*, SrcList*);
 int sqlite3IsReadOnly(Parse*, Table*, int);
 void sqlite3OpenTable(Parse*, int iCur, int iDb, Table*, int);
@@ -1783,7 +1786,7 @@ void sqlite3ChangeCookie(sqlite3*, Vdbe*, int);
   void sqlite3DropTriggerPtr(Parse*, Trigger*);
   int sqlite3TriggersExist(Parse*, Table*, int, ExprList*);
   int sqlite3CodeRowTrigger(Parse*, int, ExprList*, int, Table *, int, int, 
-                           int, int);
+                           int, int, u32*, u32*);
   void sqliteViewTriggers(Parse*, Table*, Expr*, int, ExprList*);
   void sqlite3DeleteTriggerStep(TriggerStep*);
   TriggerStep *sqlite3TriggerSelectStep(sqlite3*,Select*);
@@ -1798,7 +1801,7 @@ void sqlite3ChangeCookie(sqlite3*, Vdbe*, int);
 # define sqlite3DeleteTrigger(A)
 # define sqlite3DropTriggerPtr(A,B)
 # define sqlite3UnlinkAndDeleteTrigger(A,B,C)
-# define sqlite3CodeRowTrigger(A,B,C,D,E,F,G,H,I) 0
+# define sqlite3CodeRowTrigger(A,B,C,D,E,F,G,H,I,J,K) 0
 #endif
 
 int sqlite3JoinType(Parse*, Token*, Token*, Token*);
diff --git a/src/trigger.c b/src/trigger.c
index efcf812449..4748b4ecba 100644
--- a/src/trigger.c
+++ b/src/trigger.c
@@ -751,6 +751,13 @@ static int codeTriggerProgram(
 **    a row containing values to be substituted for old.* expressions in the
 **    trigger program(s).
 **
+** If they are not NULL, the piOldColMask and piNewColMask output variables
+** are set to values that describe the columns used by the trigger program
+** in the OLD.* and NEW.* tables respectively. If column N of the 
+** pseudo-table is read at least once, the corresponding bit of the output
+** mask is set. If a column with an index greater than 32 is read, the
+** output mask is set to the special value 0xffffffff.
+**
 */
 int sqlite3CodeRowTrigger(
   Parse *pParse,       /* Parse context */
@@ -761,11 +768,16 @@ int sqlite3CodeRowTrigger(
   int newIdx,          /* The indice of the "new" row to access */
   int oldIdx,          /* The indice of the "old" row to access */
   int orconf,          /* ON CONFLICT policy */
-  int ignoreJump       /* Instruction to jump to for RAISE(IGNORE) */
+  int ignoreJump,      /* Instruction to jump to for RAISE(IGNORE) */
+  u32 *piOldColMask,   /* OUT: Mask of columns used from the OLD.* table */
+  u32 *piNewColMask    /* OUT: Mask of columns used from the NEW.* table */
 ){
   Trigger *p;
   TriggerStack trigStackEntry;
 
+  trigStackEntry.oldColMask = 0;
+  trigStackEntry.newColMask = 0;
+
   assert(op == TK_UPDATE || op == TK_INSERT || op == TK_DELETE);
   assert(tr_tm == TRIGGER_BEFORE || tr_tm == TRIGGER_AFTER );
 
@@ -835,6 +847,8 @@ int sqlite3CodeRowTrigger(
       sqlite3VdbeResolveLabel(pParse->pVdbe, endTrigger);
     }
   }
+  if( piOldColMask ) *piOldColMask |= trigStackEntry.oldColMask;
+  if( piNewColMask ) *piNewColMask |= trigStackEntry.newColMask;
   return 0;
 }
 #endif /* !defined(SQLITE_OMIT_TRIGGER) */
diff --git a/src/update.c b/src/update.c
index bf5a5caac0..2ed1142126 100644
--- a/src/update.c
+++ b/src/update.c
@@ -12,7 +12,7 @@
 ** This file contains C code routines that are called by the parser
 ** to handle UPDATE statements.
 **
-** $Id: update.c,v 1.144 2007/12/12 16:06:23 danielk1977 Exp $
+** $Id: update.c,v 1.145 2008/01/01 19:02:09 danielk1977 Exp $
 */
 #include "sqliteInt.h"
 
@@ -111,6 +111,12 @@ void sqlite3Update(
   int isView;                  /* Trying to update a view */
   int triggers_exist = 0;      /* True if any row triggers exist */
 #endif
+  int iBeginAfterTrigger;      /* Address of after trigger program */
+  int iEndAfterTrigger;        /* Exit of after trigger program */
+  int iBeginBeforeTrigger;     /* Address of before trigger program */
+  int iEndBeforeTrigger;       /* Exit of before trigger program */
+  u32 old_col_mask = 0;        /* Mask of OLD.* columns in use */
+  u32 new_col_mask = 0;        /* Mask of NEW.* columns in use */
 
   int newIdx      = -1;  /* index of trigger "new" temp table       */
   int oldIdx      = -1;  /* index of trigger "old" temp table       */
@@ -288,12 +294,33 @@ void sqlite3Update(
     sqlite3AuthContextPush(pParse, &sContext, pTab->zName);
   }
 
+  /* Generate the code for triggers.
+  */
+  if( triggers_exist ){
+    int iGoto = sqlite3VdbeAddOp(v, OP_Goto, 0, 0);
+    addr = sqlite3VdbeMakeLabel(v);
+    iBeginBeforeTrigger = sqlite3VdbeCurrentAddr(v);
+    if( sqlite3CodeRowTrigger(pParse, TK_UPDATE, pChanges, TRIGGER_BEFORE, pTab,
+          newIdx, oldIdx, onError, addr, &old_col_mask, &new_col_mask) ){
+      goto update_cleanup;
+    }
+    iEndBeforeTrigger = sqlite3VdbeAddOp(v, OP_Goto, 0, 0);
+    iBeginAfterTrigger = sqlite3VdbeCurrentAddr(v);
+    if( sqlite3CodeRowTrigger(pParse, TK_UPDATE, pChanges, TRIGGER_AFTER, pTab, 
+          newIdx, oldIdx, onError, addr, &old_col_mask, &new_col_mask) ){
+      goto update_cleanup;
+    }
+    iEndAfterTrigger = sqlite3VdbeAddOp(v, OP_Goto, 0, 0);
+    sqlite3VdbeJumpHere(v, iGoto);
+  }
+
   /* If we are trying to update a view, realize that view into
   ** a ephemeral table.
   */
   if( isView ){
     Select *pView;
     pView = sqlite3SelectDup(db, pTab->pSelect);
+    sqlite3SelectMask(pParse, pView, old_col_mask|new_col_mask);
     sqlite3Select(pParse, pView, SRT_EphemTab, iCur, 0, 0, 0, 0);
     sqlite3SelectDelete(pView);
   }
@@ -320,7 +347,6 @@ void sqlite3Update(
   }
 
   if( triggers_exist ){
-    
     /* Create pseudo-tables for NEW and OLD
     */
     sqlite3VdbeAddOp(v, OP_OpenPseudo, oldIdx, 0);
@@ -330,6 +356,7 @@ void sqlite3Update(
 
     /* The top of the update loop for when there are triggers.
     */
+    sqlite3VdbeResolveLabel(v, addr);
     addr = sqlite3VdbeAddOp(v, OP_FifoRead, 0, 0);
     sqlite3VdbeAddOp(v, OP_StackDepth, -1, 0);
     sqlite3VdbeAddOp(v, OP_MemStore, mem1, 0);
@@ -345,7 +372,11 @@ void sqlite3Update(
     /* Generate the OLD table
     */
     sqlite3VdbeAddOp(v, OP_Rowid, iCur, 0);
-    sqlite3VdbeAddOp(v, OP_RowData, iCur, 0);
+    if( !old_col_mask ){
+      sqlite3VdbeAddOp(v, OP_Null, 0, 0);
+    }else{
+      sqlite3VdbeAddOp(v, OP_RowData, iCur, 0);
+    }
     sqlite3VdbeAddOp(v, OP_Insert, oldIdx, 0);
 
     /* Generate the NEW table
@@ -361,11 +392,15 @@ void sqlite3Update(
         continue;
       }
       j = aXRef[i];
-      if( j<0 ){
-        sqlite3VdbeAddOp(v, OP_Column, iCur, i);
-        sqlite3ColumnDefault(v, pTab, i);
+      if( new_col_mask&((u32)1<<i) || new_col_mask==0xffffffff ){
+        if( j<0 ){
+          sqlite3VdbeAddOp(v, OP_Column, iCur, i);
+          sqlite3ColumnDefault(v, pTab, i);
+        }else{
+          sqlite3ExprCodeAndCache(pParse, pChanges->a[j].pExpr);
+        }
       }else{
-        sqlite3ExprCodeAndCache(pParse, pChanges->a[j].pExpr);
+        sqlite3VdbeAddOp(v, OP_Null, 0, 0);
       }
     }
     sqlite3VdbeAddOp(v, OP_MakeRecord, pTab->nCol, 0);
@@ -378,13 +413,9 @@ void sqlite3Update(
       sqlite3VdbeAddOp(v, OP_Close, iCur, 0);
     }
 
-    /* Fire the BEFORE and INSTEAD OF triggers
-    */
-    if( sqlite3CodeRowTrigger(pParse, TK_UPDATE, pChanges, TRIGGER_BEFORE, pTab,
-          newIdx, oldIdx, onError, addr) ){
-      goto update_cleanup;
-    }
-    
+    sqlite3VdbeAddOp(v, OP_Goto, 0, iBeginBeforeTrigger);
+    sqlite3VdbeJumpHere(v, iEndBeforeTrigger);
+
     if( !isView ){
       sqlite3VdbeAddOp(v, OP_MemLoad, mem1, 0);
     }
@@ -495,10 +526,8 @@ void sqlite3Update(
       }
       sqlite3VdbeAddOp(v, OP_Close, iCur, 0);
     }
-    if( sqlite3CodeRowTrigger(pParse, TK_UPDATE, pChanges, TRIGGER_AFTER, pTab, 
-          newIdx, oldIdx, onError, addr) ){
-      goto update_cleanup;
-    }
+    sqlite3VdbeAddOp(v, OP_Goto, 0, iBeginAfterTrigger);
+    sqlite3VdbeJumpHere(v, iEndAfterTrigger);
   }
 
   /* Repeat the above with the next record to be updated, until
diff --git a/test/auth.test b/test/auth.test
index 5e43fbe1bb..591d4d99d2 100644
--- a/test/auth.test
+++ b/test/auth.test
@@ -12,7 +12,7 @@
 # focus of this script is testing the sqlite3_set_authorizer() API
 # and related functionality.
 #
-# $Id: auth.test,v 1.39 2007/11/13 10:30:26 danielk1977 Exp $
+# $Id: auth.test,v 1.40 2008/01/01 19:02:09 danielk1977 Exp $
 #
 
 set testdir [file dirname $argv0]
@@ -2246,12 +2246,12 @@ do_test auth-4.3 {
 } [list \
   SQLITE_UPDATE v1     x  main {} \
   SQLITE_READ   v1     x  main {} \
-  SQLITE_SELECT {}     {} {}   v1 \
-  SQLITE_READ   t2     a  main v1 \
-  SQLITE_READ   t2     b  main v1 \
   SQLITE_INSERT v1chng {} main r2 \
   SQLITE_READ   v1     x  main r2 \
-  SQLITE_READ   v1     x  main r2]
+  SQLITE_READ   v1     x  main r2 \
+  SQLITE_READ   t2     a  main v1 \
+  SQLITE_READ   t2     b  main v1 \
+  SQLITE_SELECT {}     {} {}   v1]
 do_test auth-4.4 {
   execsql {
     CREATE TRIGGER r3 INSTEAD OF DELETE ON v1 BEGIN
@@ -2269,11 +2269,11 @@ do_test auth-4.5 {
 } [list \
   SQLITE_DELETE v1     {} main {} \
   SQLITE_READ   v1     x  main {} \
-  SQLITE_SELECT {}     {} {}   v1 \
+  SQLITE_INSERT v1chng {} main r3 \
+  SQLITE_READ   v1     x  main r3 \
   SQLITE_READ   t2     a  main v1 \
   SQLITE_READ   t2     b  main v1 \
-  SQLITE_INSERT v1chng {} main r3 \
-  SQLITE_READ   v1     x  main r3]
+  SQLITE_SELECT {}     {} {}   v1]
 
 } ;# ifcapable view && trigger
 
diff --git a/test/trigger9.test b/test/trigger9.test
new file mode 100644
index 0000000000..afb856e5e2
--- /dev/null
+++ b/test/trigger9.test
@@ -0,0 +1,147 @@
+# 2008 January 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.
+#
+#***********************************************************************
+# This file implements regression tests for SQLite library. Specifically,
+# it tests some compiler optimizations for SQL statements featuring
+# triggers:
+#
+#
+#
+
+# trigger9-1.* -   Test that if there are no references to OLD.* cols, or a
+#                  reference to only OLD.rowid, the data is not loaded.
+#
+# trigger9-2.* -   Test that for NEW.* records populated by UPDATE 
+#                  statements, unused fields are populated with NULL values. 
+#
+# trigger9-3.* -   Test that the temporary tables used for OLD.* references
+#                  in "INSTEAD OF" triggers have NULL values in unused 
+#                  fields.
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+ifcapable {!trigger} {
+  finish_test
+  return
+}
+
+proc has_rowdata {sql} {
+  expr {[lsearch [execsql "explain $sql"] RowData]>=0}
+}
+
+do_test trigger9-1.1 {
+  execsql {
+    PRAGMA page_size = 1024;
+    CREATE TABLE t1(x, y, z);
+    INSERT INTO t1 VALUES('1', randstr(10000,10000), '2');
+    INSERT INTO t1 VALUES('2', randstr(10000,10000), '4');
+    INSERT INTO t1 VALUES('3', randstr(10000,10000), '6');
+    CREATE TABLE t2(x);
+  }
+} {}
+
+do_test trigger9-1.2.1 {
+  sqlite3 db test.db
+  execsql {
+    BEGIN;
+      CREATE TRIGGER trig1 BEFORE DELETE ON t1 BEGIN
+        INSERT INTO t2 VALUES(old.rowid);
+      END;
+      DELETE FROM t1;
+      SELECT * FROM t2;
+  }
+} {1 2 3}
+do_test trigger9-1.2.3 {
+  has_rowdata {DELETE FROM t1}
+} 0
+do_test trigger9-1.2.4 { execsql { ROLLBACK } } {}
+
+do_test trigger9-1.3.1 {
+  sqlite3 db test.db
+  execsql {
+    BEGIN;
+      CREATE TRIGGER trig1 BEFORE DELETE ON t1 BEGIN
+        INSERT INTO t2 VALUES(old.x);
+      END;
+      DELETE FROM t1;
+      SELECT * FROM t2;
+  }
+} {1 2 3}
+do_test trigger9-1.3.2 {
+  has_rowdata {DELETE FROM t1}
+} 1
+do_test trigger9-1.3.3 { execsql { ROLLBACK } } {}
+
+do_test trigger9-1.4.1 {
+  sqlite3 db test.db
+  execsql {
+    BEGIN;
+      CREATE TRIGGER trig1 BEFORE DELETE ON t1 WHEN old.x='1' BEGIN
+        INSERT INTO t2 VALUES(old.rowid);
+      END;
+      DELETE FROM t1;
+      SELECT * FROM t2;
+  }
+} {1}
+do_test trigger9-1.4.2 {
+  has_rowdata {DELETE FROM t1}
+} 1
+do_test trigger9-1.4.3 { execsql { ROLLBACK } } {}
+
+do_test trigger9-1.5.1 {
+  sqlite3 db test.db
+  execsql {
+    BEGIN;
+      CREATE TRIGGER trig1 BEFORE UPDATE ON t1 BEGIN
+        INSERT INTO t2 VALUES(old.rowid);
+      END;
+      UPDATE t1 SET y = '';
+      SELECT * FROM t2;
+  }
+} {1 2 3}
+do_test trigger9-1.5.2 {
+  has_rowdata {UPDATE t1 SET y = ''}
+} 0
+do_test trigger9-1.5.3 { execsql { ROLLBACK } } {}
+
+do_test trigger9-1.6.1 {
+  sqlite3 db test.db
+  execsql {
+    BEGIN;
+      CREATE TRIGGER trig1 BEFORE UPDATE ON t1 BEGIN
+        INSERT INTO t2 VALUES(old.x);
+      END;
+      UPDATE t1 SET y = '';
+      SELECT * FROM t2;
+  }
+} {1 2 3}
+do_test trigger9-1.6.2 {
+  has_rowdata {UPDATE t1 SET y = ''}
+} 1
+do_test trigger9-1.6.3 { execsql { ROLLBACK } } {}
+
+do_test trigger9-1.7.1 {
+  sqlite3 db test.db
+  execsql {
+    BEGIN;
+      CREATE TRIGGER trig1 BEFORE UPDATE ON t1 WHEN old.x>='2' BEGIN
+        INSERT INTO t2 VALUES(old.x);
+      END;
+      UPDATE t1 SET y = '';
+      SELECT * FROM t2;
+  }
+} {2 3}
+do_test trigger9-1.7.2 {
+  has_rowdata {UPDATE t1 SET y = ''}
+} 1
+do_test trigger9-1.7.3 { execsql { ROLLBACK } } {}
+
+finish_test