--- ext/rtree/rtree.c.ori	2017-06-28 13:16:34.102826422 +0200
+++ ext/rtree/rtree.c	2017-06-28 13:16:35.734827232 +0200
@@ -132,6 +132,9 @@
   RtreeNode *pDeleted;
   int iReinsertHeight;        /* Height of sub-trees Reinsert() has run on */
 
+  /* Blob I/O on xxx_node */
+  sqlite3_blob *pNodeBlob;
+
   /* Statements to read/write/delete a record from xxx_node */
   sqlite3_stmt *pReadNode;
   sqlite3_stmt *pWriteNode;
@@ -503,6 +506,16 @@
 }
 
 /*
+** Clear the Rtree.pNodeBlob object
+*/
+static void nodeBlobReset(Rtree *pRtree){
+  if( pRtree->pNodeBlob ){
+    sqlite3_blob_close(pRtree->pNodeBlob);
+    pRtree->pNodeBlob = 0;
+  }
+}
+
+/*
 ** Obtain a reference to an r-tree node.
 */
 static int nodeAcquire(
@@ -511,9 +524,8 @@
   RtreeNode *pParent,        /* Either the parent node or NULL */
   RtreeNode **ppNode         /* OUT: Acquired node */
 ){
-  int rc;
-  int rc2 = SQLITE_OK;
-  RtreeNode *pNode;
+  int rc = SQLITE_OK;
+  RtreeNode *pNode = 0;
 
   /* Check if the requested node is already in the hash table. If so,
   ** increase its reference count and return it.
@@ -529,28 +541,42 @@
     return SQLITE_OK;
   }
 
-  sqlite3_bind_int64(pRtree->pReadNode, 1, iNode);
-  rc = sqlite3_step(pRtree->pReadNode);
-  if( rc==SQLITE_ROW ){
-    const u8 *zBlob = sqlite3_column_blob(pRtree->pReadNode, 0);
-    if( pRtree->iNodeSize==sqlite3_column_bytes(pRtree->pReadNode, 0) ){
-      pNode = (RtreeNode *)sqlite3_malloc(sizeof(RtreeNode)+pRtree->iNodeSize);
-      if( !pNode ){
-        rc2 = SQLITE_NOMEM;
-      }else{
-        pNode->pParent = pParent;
-        pNode->zData = (u8 *)&pNode[1];
-        pNode->nRef = 1;
-        pNode->iNode = iNode;
-        pNode->isDirty = 0;
-        pNode->pNext = 0;
-        memcpy(pNode->zData, zBlob, pRtree->iNodeSize);
-        nodeReference(pParent);
-      }
+  if( pRtree->pNodeBlob ){
+    sqlite3_blob *pBlob = pRtree->pNodeBlob;
+    pRtree->pNodeBlob = 0;
+    rc = sqlite3_blob_reopen(pBlob, iNode);
+    pRtree->pNodeBlob = pBlob;
+    if( rc ){
+      nodeBlobReset(pRtree);
+      if( rc==SQLITE_NOMEM ) return rc;
+    }
+  }
+  if( pRtree->pNodeBlob==0 ){
+    char *zTab = sqlite3_mprintf("%s_node", pRtree->zName);
+    if( zTab==0 ) return SQLITE_NOMEM;
+    rc = sqlite3_blob_open(pRtree->db, pRtree->zDb, zTab, "data", iNode, 0,
+                           &pRtree->pNodeBlob);
+    sqlite3_free(zTab);
+  }
+  if( rc ){
+    nodeBlobReset(pRtree);
+    *ppNode = 0;
+  }else if( pRtree->iNodeSize==sqlite3_blob_bytes(pRtree->pNodeBlob) ){
+    pNode = (RtreeNode *)sqlite3_malloc(sizeof(RtreeNode)+pRtree->iNodeSize);
+    if( !pNode ){
+      rc = SQLITE_NOMEM;
+    }else{
+      pNode->pParent = pParent;
+      pNode->zData = (u8 *)&pNode[1];
+      pNode->nRef = 1;
+      pNode->iNode = iNode;
+      pNode->isDirty = 0;
+      pNode->pNext = 0;
+      rc = sqlite3_blob_read(pRtree->pNodeBlob, pNode->zData,
+                             pRtree->iNodeSize, 0);
+      nodeReference(pParent);
     }
   }
-  rc = sqlite3_reset(pRtree->pReadNode);
-  if( rc==SQLITE_OK ) rc = rc2;
 
   /* If the root node was just loaded, set pRtree->iDepth to the height
   ** of the r-tree structure. A height of zero means all data is stored on
@@ -793,6 +819,7 @@
 static void rtreeRelease(Rtree *pRtree){
   pRtree->nBusy--;
   if( pRtree->nBusy==0 ){
+    nodeBlobReset(pRtree);
     sqlite3_finalize(pRtree->pReadNode);
     sqlite3_finalize(pRtree->pWriteNode);
     sqlite3_finalize(pRtree->pDeleteNode);
@@ -831,6 +858,7 @@
   if( !zCreate ){
     rc = SQLITE_NOMEM;
   }else{
+    nodeBlobReset(pRtree);
     rc = sqlite3_exec(pRtree->db, zCreate, 0, 0, 0);
     sqlite3_free(zCreate);
   }
@@ -2933,6 +2961,27 @@
 }
 
 /*
+** Called when a transaction starts.
+** This is a no-op.  But the Virtual Table mechanism needs a method
+** here or else it will never call the xRollback and xCommit methods,
+** and those methods are necessary for clearing the sqlite3_blob object.
+*/
+static int rtreeBeginTransaction(sqlite3_vtab *pVtab){
+  (void)pVtab;
+  return SQLITE_OK;
+}
+
+/*
+** Called when a transaction completes (either by COMMIT or ROLLBACK).
+** The sqlite3_blob object should be released at this point.
+*/
+static int rtreeEndTransaction(sqlite3_vtab *pVtab){
+  Rtree *pRtree = (Rtree *)pVtab;
+  nodeBlobReset(pRtree);
+  return SQLITE_OK;
+}
+
+/*
 ** The xRename method for rtree module virtual tables.
 */
 static int rtreeRename(sqlite3_vtab *pVtab, const char *zNewName){
@@ -2953,6 +3002,7 @@
   return rc;
 }
 
+
 /*
 ** This function populates the pRtree->nRowEst variable with an estimate
 ** of the number of rows in the virtual table. If possible, this is based
@@ -3005,15 +3055,15 @@
   rtreeColumn,                /* xColumn - read data */
   rtreeRowid,                 /* xRowid - read data */
   rtreeUpdate,                /* xUpdate - write data */
-  0,                          /* xBegin - begin transaction */
+  rtreeBeginTransaction,      /* xBegin - begin transaction */
   0,                          /* xSync - sync transaction */
-  0,                          /* xCommit - commit transaction */
-  0,                          /* xRollback - rollback transaction */
+  rtreeEndTransaction,        /* xCommit - commit transaction */
+  rtreeEndTransaction,        /* xRollback - rollback transaction */
   0,                          /* xFindFunction - function overloading */
   rtreeRename,                /* xRename - rename the table */
   0,                          /* xSavepoint */
   0,                          /* xRelease */
-  0                           /* xRollbackTo */
+  0,                          /* xRollbackTo */
 };
 
 static int rtreeSqlInit(