Index: src/dbstat.c
==================================================================
--- src/dbstat.c
+++ src/dbstat.c
@@ -120,10 +120,11 @@
 };
 
 struct StatTable {
   sqlite3_vtab base;
   sqlite3 *db;
+  int iDb;                        /* Index of database to analyze */
 };
 
 #ifndef get2byte
 # define get2byte(x)   ((x)[0]<<8 | (x)[1])
 #endif
@@ -138,11 +139,21 @@
   sqlite3_vtab **ppVtab,
   char **pzErr
 ){
   StatTable *pTab = 0;
   int rc = SQLITE_OK;
+  int iDb;
 
+  if( argc>=4 ){
+    iDb = sqlite3FindDbName(db, argv[3]);
+    if( iDb<0 ){
+      *pzErr = sqlite3_mprintf("no such database: %s", argv[3]);
+      return SQLITE_ERROR;
+    }
+  }else{
+    iDb = 0;
+  }
   rc = sqlite3_declare_vtab(db, VTAB_SCHEMA);
   if( rc==SQLITE_OK ){
     pTab = (StatTable *)sqlite3_malloc64(sizeof(StatTable));
     if( pTab==0 ) rc = SQLITE_NOMEM;
   }
@@ -149,10 +160,11 @@
 
   assert( rc==SQLITE_OK || pTab==0 );
   if( rc==SQLITE_OK ){
     memset(pTab, 0, sizeof(StatTable));
     pTab->db = db;
+    pTab->iDb = iDb;
   }
 
   *ppVtab = (sqlite3_vtab*)pTab;
   return rc;
 }
@@ -203,20 +215,26 @@
 
   pCsr = (StatCursor *)sqlite3_malloc64(sizeof(StatCursor));
   if( pCsr==0 ){
     rc = SQLITE_NOMEM;
   }else{
+    char *zSql;
     memset(pCsr, 0, sizeof(StatCursor));
     pCsr->base.pVtab = pVTab;
 
-    rc = sqlite3_prepare_v2(pTab->db, 
+    zSql = sqlite3_mprintf(
         "SELECT 'sqlite_master' AS name, 1 AS rootpage, 'table' AS type"
         "  UNION ALL  "
-        "SELECT name, rootpage, type FROM sqlite_master WHERE rootpage!=0"
-        "  ORDER BY name", -1,
-        &pCsr->pStmt, 0
-        );
+        "SELECT name, rootpage, type"
+        "  FROM \"%w\".sqlite_master WHERE rootpage!=0"
+        "  ORDER BY name", pTab->db->aDb[pTab->iDb].zName);
+    if( zSql==0 ){
+      rc = SQLITE_NOMEM;
+    }else{
+      rc = sqlite3_prepare_v2(pTab->db, zSql, -1, &pCsr->pStmt, 0);
+      sqlite3_free(zSql);
+    }
     if( rc!=SQLITE_OK ){
       sqlite3_free(pCsr);
       pCsr = 0;
     }
   }
@@ -378,11 +396,11 @@
 ** Populate the pCsr->iOffset and pCsr->szPage member variables. Based on
 ** the current value of pCsr->iPageno.
 */
 static void statSizeAndOffset(StatCursor *pCsr){
   StatTable *pTab = (StatTable *)((sqlite3_vtab_cursor *)pCsr)->pVtab;
-  Btree *pBt = pTab->db->aDb[0].pBt;
+  Btree *pBt = pTab->db->aDb[pTab->iDb].pBt;
   Pager *pPager = sqlite3BtreePager(pBt);
   sqlite3_file *fd;
   sqlite3_int64 x[2];
 
   /* The default page size and offset */
@@ -392,11 +410,11 @@
   /* If connected to a ZIPVFS backend, override the page size and
   ** offset with actual values obtained from ZIPVFS.
   */
   fd = sqlite3PagerFile(pPager);
   x[0] = pCsr->iPageno;
-  if( sqlite3OsFileControl(fd, 230440, &x)==SQLITE_OK ){
+  if( fd->pMethods!=0 && sqlite3OsFileControl(fd, 230440, &x)==SQLITE_OK ){
     pCsr->iOffset = x[0];
     pCsr->szPage = (int)x[1];
   }
 }
 
@@ -406,11 +424,11 @@
 static int statNext(sqlite3_vtab_cursor *pCursor){
   int rc;
   int nPayload;
   StatCursor *pCsr = (StatCursor *)pCursor;
   StatTable *pTab = (StatTable *)pCursor->pVtab;
-  Btree *pBt = pTab->db->aDb[0].pBt;
+  Btree *pBt = pTab->db->aDb[pTab->iDb].pBt;
   Pager *pPager = sqlite3BtreePager(pBt);
 
   sqlite3_free(pCsr->zPath);
   pCsr->zPath = 0;
 

Index: test/stat.test
==================================================================
--- test/stat.test
+++ test/stat.test
@@ -164,12 +164,14 @@
 forcedelete test.db
 sqlite3 db test.db
 register_dbstat_vtab db
 do_execsql_test stat-5.1 {
   PRAGMA auto_vacuum = OFF;
-  CREATE VIRTUAL TABLE temp.stat USING dbstat;
-  CREATE TABLE t1(x);
+  CREATE TABLE tx(y);
+  ATTACH ':memory:' AS aux1;
+  CREATE VIRTUAL TABLE temp.stat USING dbstat(aux1);
+  CREATE TABLE aux1.t1(x);
   INSERT INTO t1 VALUES(zeroblob(1513));
   INSERT INTO t1 VALUES(zeroblob(1514));
   SELECT name, path, pageno, pagetype, ncell, payload, unused, mx_payload
     FROM stat WHERE name = 't1';
 } [list \
@@ -176,6 +178,10 @@
   t1 / 2 leaf 2 993 5 1517                \
   t1 /000+000000 3 overflow 0 1020 0 0    \
   t1 /001+000000 4 overflow 0 1020 0 0    \
 ]
 
+do_catchsql_test stat-6.1 {
+  CREATE VIRTUAL TABLE temp.s2 USING dbstat(mainx);
+} {1 {no such database: mainx}}
+
 finish_test