Index: Makefile.in
==================================================================
--- Makefile.in
+++ Makefile.in
@@ -586,10 +586,14 @@
 		$(TOP)/src/shell.c sqlite3.c \
 		$(LIBREADLINE) $(TLIBS) -rpath "$(libdir)"
 
 sqldiff$(TEXE):	$(TOP)/tool/sqldiff.c sqlite3.c sqlite3.h
 	$(LTLINK) -o $@ $(TOP)/tool/sqldiff.c sqlite3.c $(TLIBS)
+
+scrub$(TEXE):	$(TOP)/ext/misc/scrub.c sqlite3.o
+	$(LTLINK) -o $@ -I. -DSCRUB_STANDALONE \
+		$(TOP)/ext/misc/scrub.c sqlite3.o $(TLIBS)
 
 srcck1$(BEXE):	$(TOP)/tool/srcck1.c
 	$(BCC) -o srcck1$(BEXE) $(TOP)/tool/srcck1.c
 
 sourcetest:	srcck1$(BEXE) sqlite3.c

Index: Makefile.msc
==================================================================
--- Makefile.msc
+++ Makefile.msc
@@ -1453,10 +1453,13 @@
 
 # <<mark>>
 sqldiff.exe:	$(TOP)\tool\sqldiff.c $(SQLITE3C) $(SQLITE3H)
 	$(LTLINK) $(NO_WARN) $(TOP)\tool\sqldiff.c $(SQLITE3C) /link $(LDFLAGS) $(LTLINKOPTS)
 
+scrub.exe:	$(TOP)\ext\misc\scrub.c $(SQLITE3C) $(SQLITE3H)
+	$(LTLINK) $(NO_WARN) $(TOP)\ext\misc\scrub.c $(SQLITE3C) /link $(LDFLAGS) $(LTLINKOPTS)
+
 srcck1.exe:	$(TOP)\tool\srcck1.c
 	$(BCC) $(NO_WARN) -Fe$@ $(TOP)\tool\srcck1.c
 
 sourcetest:	srcck1.exe sqlite3.c
 	srcck1.exe sqlite3.c

ADDED   ext/misc/scrub.c
Index: ext/misc/scrub.c
==================================================================
--- /dev/null
+++ ext/misc/scrub.c
@@ -0,0 +1,306 @@
+/*
+** 2016-05-05
+**
+** 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 a utility function (and a utility program) that
+** makes a copy of an SQLite database while simultaneously zeroing out all
+** deleted content.
+**
+** Normally (when PRAGMA secure_delete=OFF, which is the default) when SQLite
+** deletes content, it does not overwrite the deleted content but rather marks
+** the region of the file that held that content as being reusable.  This can
+** cause deleted content to recoverable from the database file.  This stale
+** content is removed by the VACUUM command, but VACUUM can be expensive for
+** large databases.  When in PRAGMA secure_delete=ON mode, the deleted content
+** is zeroed, but secure_delete=ON has overhead as well.
+**
+** This utility attempts to make a copy of a complete SQLite database where
+** all of the deleted content is zeroed out in the copy, and it attempts to
+** do so while being faster than running VACUUM.
+**
+** Usage:
+**
+**   int sqlite3_scrub_backup(
+**       const char *zSourceFile,   // Source database filename
+**       const char *zDestFile,     // Destination database filename
+**       char **pzErrMsg            // Write error message here
+**   );
+**
+** Simply call the API above specifying the filename of the source database
+** and the name of the backup copy.  The source database must already exist
+** and can be in active use. (A read lock is held during the backup.)  The
+** destination file should not previously exist.  If the pzErrMsg parameter
+** is non-NULL and if an error occurs, then an error message might be written
+** into memory obtained from sqlite3_malloc() and *pzErrMsg made to point to
+** that error message.  But if the error is an OOM, the error might not be
+** reported.  The routine always returns non-zero if there is an error.
+**
+** If compiled with -DSCRUB_STANDALONE then a main() procedure is added and
+** this file becomes a standalone program that can be run as follows:
+**
+**      ./sqlite3scrub SOURCE DEST
+*/
+#include "sqlite3.h"
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <string.h>
+
+typedef struct ScrubState ScrubState;
+typedef unsigned char u8;
+
+/* State information for a scrub-and-backup operation */
+struct ScrubState {
+  const char *zSrcFile;    /* Name of the source file */
+  const char *zDestFile;   /* Name of the destination file */
+  int rcErr;               /* Error code */
+  char *zErr;              /* Error message text */
+  sqlite3 *dbSrc;          /* Source database connection */
+  sqlite3_file *pSrc;      /* Source file handle */
+  sqlite3 *dbDest;         /* Destination database connection */
+  sqlite3_file *pDest;     /* Destination file handle */
+  unsigned int szPage;     /* Page size */
+  unsigned int nPage;      /* Number of pages */
+  u8 *page1;               /* Content of page 1 */
+};
+
+/* Store an error message */
+static void scrubBackupErr(ScrubState *p, const char *zFormat, ...){
+  va_list ap;
+  sqlite3_free(p->zErr);
+  va_start(ap, zFormat);
+  p->zErr = sqlite3_vmprintf(zFormat, ap);
+  va_end(ap);
+  if( p->rcErr==0 ) p->rcErr = SQLITE_ERROR;
+}
+
+/* Allocate memory to hold a single page of content */
+static u8 *scrubBackupAllocPage(ScrubState *p){
+  u8 *pPage;
+  if( p->rcErr ) return 0;
+  pPage = sqlite3_malloc( p->szPage );
+  if( pPage==0 ) p->rcErr = SQLITE_NOMEM;
+  return pPage;
+}
+
+/* Read a page from the source database into memory.  Use the memory
+** provided by pBuf if not NULL or allocate a new page if pBuf==NULL.
+*/
+static u8 *scrubBackupRead(ScrubState *p, int pgno, u8 *pBuf){
+  int rc;
+  sqlite3_int64 iOff;
+  u8 *pOut = pBuf;
+  if( p->rcErr ) return 0;
+  if( pOut==0 ){
+    pOut = scrubBackupAllocPage(p);
+    if( pOut==0 ) return 0;
+  }
+  iOff = (pgno-1)*(sqlite3_int64)p->szPage;
+  rc = p->pSrc->pMethods->xRead(p->pSrc, pOut, p->szPage, iOff);
+  if( rc!=SQLITE_OK ){
+    if( pBuf==0 ) sqlite3_free(pOut);
+    pOut = 0;
+    scrubBackupErr(p, "read failed for page %d", pgno);
+    p->rcErr = SQLITE_IOERR;
+  }
+  return pOut;  
+}
+
+/* Write a page to the destination database */
+static void scrubBackupWrite(ScrubState *p, int pgno, u8 *pData){
+  int rc;
+  sqlite3_int64 iOff;
+  if( p->rcErr ) return;
+  iOff = (pgno-1)*(sqlite3_int64)p->szPage;
+  rc = p->pDest->pMethods->xWrite(p->pDest, pData, p->szPage, iOff);
+  if( rc!=SQLITE_OK ){
+    scrubBackupErr(p, "write failed for page %d", pgno);
+    p->rcErr = SQLITE_IOERR;
+  }
+}
+
+/* Prepare a statement against the "db" database. */
+static sqlite3_stmt *scrubBackupPrepare(
+  ScrubState *p,      /* Backup context */
+  sqlite3 *db,        /* Database to prepare against */
+  const char *zSql    /* SQL statement */
+){
+  sqlite3_stmt *pStmt;
+  if( p->rcErr ) return 0;
+  p->rcErr = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);
+  if( p->rcErr ){
+    scrubBackupErr(p, "SQL error \"%s\" on \"%s\"",
+                   sqlite3_errmsg(db), zSql);
+    sqlite3_finalize(pStmt);
+    return 0;
+  }
+  return pStmt;
+}
+
+
+/* Open the source database file */
+static void scrubBackupOpenSrc(ScrubState *p){
+  sqlite3_stmt *pStmt;
+  int rc;
+  /* Open the source database file */
+  p->rcErr = sqlite3_open_v2(p->zSrcFile, &p->dbSrc,
+                 SQLITE_OPEN_READONLY |
+                 SQLITE_OPEN_URI | SQLITE_OPEN_PRIVATECACHE, 0);
+  if( p->rcErr ){
+    scrubBackupErr(p, "cannot open source database: %s",
+                      sqlite3_errmsg(p->dbSrc));
+    return;
+  }
+  p->rcErr = sqlite3_exec(p->dbSrc, "BEGIN", 0, 0, 0);
+  if( p->rcErr ){
+    scrubBackupErr(p,
+       "cannot start a read transaction on the source database: %s",
+       sqlite3_errmsg(p->dbSrc));
+    return;
+  }
+  pStmt = scrubBackupPrepare(p, p->dbSrc, "PRAGMA page_size");
+  if( pStmt==0 ) return;
+  rc = sqlite3_step(pStmt);
+  if( rc==SQLITE_ROW ){
+    p->szPage = sqlite3_column_int(pStmt, 0);
+  }else{
+    scrubBackupErr(p, "unable to determine the page size");
+  }
+  sqlite3_finalize(pStmt);
+  if( p->rcErr ) return;
+  pStmt = scrubBackupPrepare(p, p->dbSrc, "PRAGMA page_count");
+  if( pStmt==0 ) return;
+  rc = sqlite3_step(pStmt);
+  if( rc==SQLITE_ROW ){
+    p->nPage = sqlite3_column_int(pStmt, 0);
+  }else{
+    scrubBackupErr(p, "unable to determine the size of the source database");
+  }
+  sqlite3_finalize(pStmt);
+  sqlite3_file_control(p->dbSrc, "main", SQLITE_FCNTL_FILE_POINTER, &p->pSrc);
+  if( p->pSrc==0 || p->pSrc->pMethods==0 ){
+    scrubBackupErr(p, "cannot get the source file handle");
+    p->rcErr = SQLITE_ERROR;
+  }
+}
+
+/* Create and open the destination file */
+static void scrubBackupOpenDest(ScrubState *p){
+  sqlite3_stmt *pStmt;
+  int rc;
+  char *zSql;
+  if( p->rcErr ) return;
+  p->rcErr = sqlite3_open_v2(p->zDestFile, &p->dbDest,
+                 SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE |
+                 SQLITE_OPEN_URI | SQLITE_OPEN_PRIVATECACHE, 0);
+  if( p->rcErr ){
+    scrubBackupErr(p, "cannot open destination database: %s",
+                      sqlite3_errmsg(p->dbDest));
+    return;
+  }
+  zSql = sqlite3_mprintf("PRAGMA page_size(%u);", p->szPage);
+  if( zSql==0 ){
+    p->rcErr = SQLITE_NOMEM;
+    return;
+  }
+  p->rcErr = sqlite3_exec(p->dbDest, zSql, 0, 0, 0);
+  sqlite3_free(zSql);
+  if( p->rcErr ){
+    scrubBackupErr(p,
+       "cannot set the page size on the destination database: %s",
+       sqlite3_errmsg(p->dbDest));
+    return;
+  }
+  sqlite3_exec(p->dbDest, "PRAGMA journal_mode=OFF;", 0, 0, 0);
+  p->rcErr = sqlite3_exec(p->dbDest, "BEGIN EXCLUSIVE;", 0, 0, 0);
+  if( p->rcErr ){
+    scrubBackupErr(p,
+       "cannot start a write transaction on the destination database: %s",
+       sqlite3_errmsg(p->dbDest));
+    return;
+  }
+  pStmt = scrubBackupPrepare(p, p->dbDest, "PRAGMA page_count;");
+  if( pStmt==0 ) return;
+  rc = sqlite3_step(pStmt);
+  if( rc!=SQLITE_ROW ){
+    scrubBackupErr(p, "cannot measure the size of the destination");
+  }else if( sqlite3_column_int(pStmt, 0)>1 ){
+    scrubBackupErr(p, "destination database is not empty - holds %d pages",
+                   sqlite3_column_int(pStmt, 0));
+  }
+  sqlite3_finalize(pStmt);
+  sqlite3_file_control(p->dbDest, "main", SQLITE_FCNTL_FILE_POINTER, &p->pDest);
+  if( p->pDest==0 || p->pDest->pMethods==0 ){
+    scrubBackupErr(p, "cannot get the destination file handle");
+    p->rcErr = SQLITE_ERROR;
+  }
+}
+
+int sqlite3_scrub_backup(
+  const char *zSrcFile,    /* Source file */
+  const char *zDestFile,   /* Destination file */
+  char **pzErr             /* Write error here if non-NULL */
+){
+  ScrubState s;
+  unsigned int i;
+  u8 *pBuf = 0;
+  u8 *pData;
+
+  memset(&s, 0, sizeof(s));
+  s.zSrcFile = zSrcFile;
+  s.zDestFile = zDestFile;
+
+  scrubBackupOpenSrc(&s);
+  scrubBackupOpenDest(&s);
+  pBuf = scrubBackupAllocPage(&s);
+
+  for(i=1; s.rcErr==0 && i<=s.nPage; i++){
+    pData = scrubBackupRead(&s, i, pBuf);
+    scrubBackupWrite(&s, i, pData);
+  }
+
+  /* Close the destination database without closing the transaction. If we
+  ** commit, page zero will be overwritten. */
+  sqlite3_close(s.dbDest);
+
+  sqlite3_close(s.dbSrc);
+  sqlite3_free(s.page1);
+  if( pzErr ){
+    *pzErr = s.zErr;
+  }else{
+    sqlite3_free(s.zErr);
+  }
+  return s.rcErr;
+}   
+
+#ifdef SCRUB_STANDALONE
+/* The main() routine when this utility is run as a stand-alone program */
+int main(int argc, char **argv){
+  char *zErr = 0;
+  int rc;
+  if( argc!=3 ){
+    fprintf(stderr,"Usage: %s SOURCE DESTINATION\n", argv[0]);
+    exit(1);
+  }
+  rc = sqlite3_scrub_backup(argv[1], argv[2], &zErr);
+  if( rc==SQLITE_NOMEM ){
+    fprintf(stderr, "%s: out of memory\n", argv[0]);
+    exit(1);
+  }
+  if( zErr ){
+    fprintf(stderr, "%s: %s\n", argv[0], zErr);
+    sqlite3_free(zErr);
+    exit(1);
+  }
+  return 0;
+}
+#endif

Index: main.mk
==================================================================
--- main.mk
+++ main.mk
@@ -486,10 +486,13 @@
 
 sqldiff$(EXE):	$(TOP)/tool/sqldiff.c sqlite3.c sqlite3.h
 	$(TCCX) -o sqldiff$(EXE) -DSQLITE_THREADSAFE=0 \
 		$(TOP)/tool/sqldiff.c sqlite3.c $(TLIBS) $(THREADLIB)
 
+scrub$(EXE):	$(TOP)/ext/misc/scrub.c sqlite3.o
+	$(TCC) -I. -DSCRUB_STANDALONE -o scrub$(EXE) $(TOP)/ext/misc/scrub.c sqlite3.o $(THREADLIB)
+
 srcck1$(EXE):	$(TOP)/tool/srcck1.c
 	$(BCC) -o srcck1$(EXE) $(TOP)/tool/srcck1.c
 
 sourcetest:	srcck1$(EXE) sqlite3.c
 	./srcck1 sqlite3.c