diff --git a/manifest b/manifest
index 116b2466ba..18ce942edb 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Fix\serrors\sin\sthe\sEBCDIC\supper-case\sto\slower-case\stranslation\stable.
-D 2015-02-19T17:16:14.345
+C Keep\strack\sof\sthe\soptimal\snumber\sof\sreserved\sbytes\s(by\slooking\sat\sreserve\nbyte\srequests\sin\scalls\sto\ssqlite3BtreeSetPageSize())\sand\sthen\schange\sthe\nreserve\sbyte\scount\sto\sthe\soptimal\swhen\sdoing\sa\sVACUUM\sor\swhen\susing\sthe\nbackup\sAPI.
+D 2015-02-21T00:19:25.084
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 6b9e7677829aa94b9f30949656e27312aefb9a46
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -168,14 +168,14 @@ F sqlite3.1 fc7ad8990fc8409983309bb80de8c811a7506786
 F sqlite3.pc.in 48fed132e7cb71ab676105d2a4dc77127d8c1f3a
 F src/alter.c ba266a779bc7ce10e52e59e7d3dc79fa342e8fdb
 F src/analyze.c 91540f835163d5369ccbae78e2e6c74d0dd53c1d
-F src/attach.c 7f6b3fafa2290b407e4a94dcf1afda7ec0fe394b
+F src/attach.c 880f9b8641a829c563e52dd13c452ce457ae4dd8
 F src/auth.c b56c78ebe40a2110fd361379f7e8162d23f92240
-F src/backup.c 7ddee9c7d505e07e959a575b18498f17c71e53ea
+F src/backup.c ff743689c4d6c5cb55ad42ed9d174b2b3e71f1e3
 F src/bitvec.c 19a4ba637bd85f8f63fc8c9bae5ade9fb05ec1cb
 F src/btmutex.c 49ca66250c7dfa844a4d4cb8272b87420d27d3a5
-F src/btree.c 2a1245df0356a229bcd0fd87a8536b5067f16e82
-F src/btree.h 94277c1d30c0b75705974bcc8b0c05e79c03d474
-F src/btreeInt.h a3d0ae1d511365e1a2b76ad10960dbe55c286f34
+F src/btree.c a31ac00e30fb7bb49e90e48ce29ef8a61591be96
+F src/btree.h 9cbbb92aab22ef8b50493c40aa3f8de87c43a2fb
+F src/btreeInt.h 2bfefc01875d8da066504c233ec259fcb3b2ef72
 F src/build.c ba45ebd02904e84d98839a6ea74c3eb948596587
 F src/callback.c 7b44ce59674338ad48b0e84e7b72f935ea4f68b0
 F src/complete.c 198a0066ba60ab06fc00fba1998d870a4d575463
@@ -278,7 +278,7 @@ F src/test_rtree.c bfe6f4386517f70054311109f3528adffec34485
 F src/test_schema.c 2bdba21b82f601da69793e1f1d11bf481a79b091
 F src/test_server.c a2615049954cbb9cfb4a62e18e2f0616e4dc38fe
 F src/test_sqllog.c b690c12933f50ff46491e0d56a251f84ae16e914
-F src/test_stat.c 9898687a6c2beca733b0dd6fe19163d987826d31
+F src/test_stat.c ffc8177f6e69de32a8a89fa6bca73facb6c5face
 F src/test_superlock.c 06797157176eb7085027d9dd278c0d7a105e3ec9
 F src/test_syscall.c 2e21ca7f7dc54a028f1967b63f1e76155c356f9b
 F src/test_tclvar.c f4dc67d5f780707210d6bb0eb6016a431c04c7fa
@@ -292,7 +292,7 @@ F src/trigger.c 25571661fdeae8c7f975ff40ffec205520a3f92f
 F src/update.c 3c4ecc282accf12d39edb8d524cf089645e55a13
 F src/utf.c fc6b889ba0779b7722634cdeaa25f1930d93820c
 F src/util.c 98a7627ca48ad3265b6940915a1d08355eb3fc7e
-F src/vacuum.c 9b30ec729337dd012ed88d4c292922c8ef9cf00c
+F src/vacuum.c 9460b9de7b2d4e34b0d374894aa6c8a0632be8ec
 F src/vdbe.c ddfc977981cd6324668aa6b114045eb1c677421a
 F src/vdbe.h 6fc69d9c5e146302c56e163cb4b31d1ee64a18c3
 F src/vdbeInt.h bb56fd199d8af1a2c1b9639ee2f70724b4338e3a
@@ -1239,7 +1239,7 @@ F tool/vdbe_profile.tcl 67746953071a9f8f2f668b73fe899074e2c6d8c1
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh 0abfd78ceb09b7f7c27c688c8e3fe93268a13b32
 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
-P 8215727dda384351765ab1d5c53ea80775b4ec65
-R ed42099f889d81b7ba10262d93840087
+P 905009f6723040d4da4776b6fd07e83c628dea2b
+R 9a7352553472f105646c8fe233cf7b38
 U drh
-Z c9abd15eefd1ceffcd5e72613bc587bc
+Z d63bd336672b94104d11cd96538a1a36
diff --git a/manifest.uuid b/manifest.uuid
index e2d70db74c..67f04903f9 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-905009f6723040d4da4776b6fd07e83c628dea2b
\ No newline at end of file
+28c2b726285ea88b334acfd6390a057d2d244838
\ No newline at end of file
diff --git a/src/attach.c b/src/attach.c
index de8742938b..7e35fa67c6 100644
--- a/src/attach.c
+++ b/src/attach.c
@@ -191,7 +191,7 @@ static void attachFunc(
       case SQLITE_NULL:
         /* No key specified.  Use the key from the main database */
         sqlite3CodecGetKey(db, 0, (void**)&zKey, &nKey);
-        if( nKey>0 || sqlite3BtreeGetReserve(db->aDb[0].pBt)>0 ){
+        if( nKey>0 || sqlite3BtreeGetOptimalReserve(db->aDb[0].pBt)>0 ){
           rc = sqlite3CodecAttach(db, db->nDb-1, zKey, nKey);
         }
         break;
diff --git a/src/backup.c b/src/backup.c
index e3f869035e..81c8b5c5f4 100644
--- a/src/backup.c
+++ b/src/backup.c
@@ -247,7 +247,7 @@ static int backupOnePage(
   ** guaranteed that the shared-mutex is held by this thread, handle
   ** p->pSrc may not actually be the owner.  */
   int nSrcReserve = sqlite3BtreeGetReserveNoMutex(p->pSrc);
-  int nDestReserve = sqlite3BtreeGetReserve(p->pDest);
+  int nDestReserve = sqlite3BtreeGetOptimalReserve(p->pDest);
 #endif
   int rc = SQLITE_OK;
   i64 iOff;
diff --git a/src/btree.c b/src/btree.c
index eb5151351c..8957b74c19 100644
--- a/src/btree.c
+++ b/src/btree.c
@@ -2405,6 +2405,9 @@ int sqlite3BtreeSetPageSize(Btree *p, int pageSize, int nReserve, int iFix){
   BtShared *pBt = p->pBt;
   assert( nReserve>=-1 && nReserve<=255 );
   sqlite3BtreeEnter(p);
+#if SQLITE_HAS_CODEC
+  if( nReserve>pBt->optimalReserve ) pBt->optimalReserve = (u8)nReserve;
+#endif
   if( pBt->btsFlags & BTS_PAGESIZE_FIXED ){
     sqlite3BtreeLeave(p);
     return SQLITE_READONLY;
@@ -2434,7 +2437,6 @@ int sqlite3BtreeGetPageSize(Btree *p){
   return p->pBt->pageSize;
 }
 
-#if defined(SQLITE_HAS_CODEC) || defined(SQLITE_DEBUG)
 /*
 ** This function is similar to sqlite3BtreeGetReserve(), except that it
 ** may only be called if it is guaranteed that the b-tree mutex is already
@@ -2447,25 +2449,33 @@ int sqlite3BtreeGetPageSize(Btree *p){
 ** database handle that owns *p, causing undefined behavior.
 */
 int sqlite3BtreeGetReserveNoMutex(Btree *p){
+  int n;
   assert( sqlite3_mutex_held(p->pBt->mutex) );
-  return p->pBt->pageSize - p->pBt->usableSize;
+  n = p->pBt->pageSize - p->pBt->usableSize;
+  return n;
 }
-#endif /* SQLITE_HAS_CODEC || SQLITE_DEBUG */
 
-#if !defined(SQLITE_OMIT_PAGER_PRAGMAS) || !defined(SQLITE_OMIT_VACUUM)
 /*
 ** Return the number of bytes of space at the end of every page that
 ** are intentually left unused.  This is the "reserved" space that is
 ** sometimes used by extensions.
+**
+** If SQLITE_HAS_MUTEX is defined then the number returned is the
+** greater of the current reserved space and the maximum requested
+** reserve space.
 */
-int sqlite3BtreeGetReserve(Btree *p){
+int sqlite3BtreeGetOptimalReserve(Btree *p){
   int n;
   sqlite3BtreeEnter(p);
-  n = p->pBt->pageSize - p->pBt->usableSize;
+  n = sqlite3BtreeGetReserveNoMutex(p);
+#ifdef SQLITE_HAS_CODEC
+  if( n<p->pBt->optimalReserve ) n = p->pBt->optimalReserve;
+#endif
   sqlite3BtreeLeave(p);
   return n;
 }
 
+
 /*
 ** Set the maximum page count for a database if mxPage is positive.
 ** No changes are made if mxPage is 0 or negative.
@@ -2496,7 +2506,6 @@ int sqlite3BtreeSecureDelete(Btree *p, int newFlag){
   sqlite3BtreeLeave(p);
   return b;
 }
-#endif /* !defined(SQLITE_OMIT_PAGER_PRAGMAS) || !defined(SQLITE_OMIT_VACUUM) */
 
 /*
 ** Change the 'auto-vacuum' property of the database. If the 'autoVacuum'
diff --git a/src/btree.h b/src/btree.h
index b57d500c77..77d12f78d3 100644
--- a/src/btree.h
+++ b/src/btree.h
@@ -73,10 +73,8 @@ int sqlite3BtreeGetPageSize(Btree*);
 int sqlite3BtreeMaxPageCount(Btree*,int);
 u32 sqlite3BtreeLastPage(Btree*);
 int sqlite3BtreeSecureDelete(Btree*,int);
-int sqlite3BtreeGetReserve(Btree*);
-#if defined(SQLITE_HAS_CODEC) || defined(SQLITE_DEBUG)
+int sqlite3BtreeGetOptimalReserve(Btree*);
 int sqlite3BtreeGetReserveNoMutex(Btree *p);
-#endif
 int sqlite3BtreeSetAutoVacuum(Btree *, int);
 int sqlite3BtreeGetAutoVacuum(Btree *);
 int sqlite3BtreeBeginTrans(Btree*,int);
diff --git a/src/btreeInt.h b/src/btreeInt.h
index ed4d75ee9f..87d0ef1bb8 100644
--- a/src/btreeInt.h
+++ b/src/btreeInt.h
@@ -418,6 +418,9 @@ struct BtShared {
 #endif
   u8 inTransaction;     /* Transaction state */
   u8 max1bytePayload;   /* Maximum first byte of cell for a 1-byte payload */
+#ifdef SQLITE_HAS_CODEC
+  u8 optimalReserve;    /* Desired amount of reserved space per page */
+#endif
   u16 btsFlags;         /* Boolean parameters.  See BTS_* macros below */
   u16 maxLocal;         /* Maximum local payload in non-LEAFDATA tables */
   u16 minLocal;         /* Minimum local payload in non-LEAFDATA tables */
diff --git a/src/test_stat.c b/src/test_stat.c
index 615df3d80f..daa84de2c0 100644
--- a/src/test_stat.c
+++ b/src/test_stat.c
@@ -301,8 +301,11 @@ static int statDecodePage(Btree *pBt, StatPage *p){
 
   if( p->nCell ){
     int i;                        /* Used to iterate through cells */
-    int nUsable = szPage - sqlite3BtreeGetReserve(pBt);
+    int nUsable;                  /* Usable bytes per page */
 
+    sqlite3BtreeEnter(pBt);
+    nUsable = szPage - sqlite3BtreeGetReserveNoMutex(pBt);
+    sqlite3BtreeLeave(pBt);
     p->aCell = sqlite3_malloc((p->nCell+1) * sizeof(StatCell));
     memset(p->aCell, 0, (p->nCell+1) * sizeof(StatCell));
 
@@ -425,7 +428,11 @@ statNextRestart:
     while( p->iCell<p->nCell ){
       StatCell *pCell = &p->aCell[p->iCell];
       if( pCell->iOvfl<pCell->nOvfl ){
-        int nUsable = sqlite3BtreeGetPageSize(pBt)-sqlite3BtreeGetReserve(pBt);
+        int nUsable;
+        sqlite3BtreeEnter(pBt);
+        nUsable = sqlite3BtreeGetPageSize(pBt) - 
+                        sqlite3BtreeGetReserveNoMutex(pBt);
+        sqlite3BtreeLeave(pBt);
         pCsr->zName = (char *)sqlite3_column_text(pCsr->pStmt, 0);
         pCsr->iPageno = pCell->aOvfl[pCell->iOvfl];
         pCsr->zPagetype = "overflow";
diff --git a/src/vacuum.c b/src/vacuum.c
index 9df8e08b22..dca43e217e 100644
--- a/src/vacuum.c
+++ b/src/vacuum.c
@@ -184,7 +184,7 @@ int sqlite3RunVacuum(char **pzErrMsg, sqlite3 *db){
   ** cause problems for the call to BtreeSetPageSize() below.  */
   sqlite3BtreeCommit(pTemp);
 
-  nRes = sqlite3BtreeGetReserve(pMain);
+  nRes = sqlite3BtreeGetOptimalReserve(pMain);
 
   /* A VACUUM cannot change the pagesize of an encrypted database. */
 #ifdef SQLITE_HAS_CODEC