Fossil

  memset(pApndFile, 0, sizeof(ApndFile));
  pFile->pMethods = &apnd_io_methods;
  pApndFile->iMark = -1;    /* Append mark not yet written */

  rc = pBaseVfs->xOpen(pBaseVfs, zName, pBaseFile, flags, pOutFlags);
  if( rc==SQLITE_OK ){
    rc = pBaseFile->pMethods->xFileSize(pBaseFile, &sz);

    if( rc ){
      pBaseFile->pMethods->xClose(pBaseFile);
    }
  }
  if( rc ){
    pFile->pMethods = 0;
    return rc;
  }
  if( apndIsOrdinaryDatabaseFile(sz, pBaseFile) ){
    /* The file being opened appears to be just an ordinary DB. Copy
    ** the base dispatch-table so this instance mimics the base VFS. 
    */

  sqlite3_db_config(p->db, SQLITE_DBCONFIG_DEFENSIVE, -1, &defensiveMode);
  sqlite3_db_config(p->db, SQLITE_DBCONFIG_DEFENSIVE, 0, 0);
  sqlite3_db_config(p->db, SQLITE_DBCONFIG_WRITABLE_SCHEMA, -1, &wrSchema);
  sqlite3_db_config(p->db, SQLITE_DBCONFIG_WRITABLE_SCHEMA, 1, 0);
  sqlite3_exec(p->db,
    "CREATE TABLE IF NOT EXISTS temp.sqlite_parameters(\n"
    "  key TEXT PRIMARY KEY,\n"
    "  value\n"
    ") WITHOUT ROWID;",
    0, 0, 0);
  sqlite3_db_config(p->db, SQLITE_DBCONFIG_WRITABLE_SCHEMA, wrSchema, 0);
  sqlite3_db_config(p->db, SQLITE_DBCONFIG_DEFENSIVE, defensiveMode, 0);
}

/*

  const char *zSql =
  "SELECT "
    "     'EXPLAIN QUERY PLAN SELECT 1 FROM ' || quote(s.name) || ' WHERE '"
    "  || group_concat(quote(s.name) || '.' || quote(f.[from]) || '=?' "
    "  || fkey_collate_clause("
    "       f.[table], COALESCE(f.[to], p.[name]), s.name, f.[from]),' AND ')"
    ", "
    "     'SEARCH ' || s.name || ' USING COVERING INDEX*('"
    "  || group_concat('*=?', ' AND ') || ')'"
    ", "
    "     s.name  || '(' || group_concat(f.[from],  ', ') || ')'"
    ", "
    "     f.[table] || '(' || group_concat(COALESCE(f.[to], p.[name])) || ')'"
    ", "
    "     'CREATE INDEX ' || quote(s.name ||'_'|| group_concat(f.[from], '_'))"
    "  || ' ON ' || quote(s.name) || '('"
    "  || group_concat(quote(f.[from]) ||"
    "        fkey_collate_clause("
    "          f.[table], COALESCE(f.[to], p.[name]), s.name, f.[from]), ', ')"
    "  || ');'"
    ", "
    "     f.[table] "
    "FROM sqlite_schema AS s, pragma_foreign_key_list(s.name) AS f "
    "LEFT JOIN pragma_table_info AS p ON (pk-1=seq AND p.arg=f.[table]) "
    "GROUP BY s.name, f.id "
    "ORDER BY (CASE WHEN ? THEN f.[table] ELSE s.name END)"
  ;
  const char *zGlobIPK = "SEARCH * USING INTEGER PRIMARY KEY (rowid=?)";

  for(i=2; i<nArg; i++){
    int n = strlen30(azArg[i]);
    if( n>1 && sqlite3_strnicmp("-verbose", azArg[i], n)==0 ){
      bVerbose = 1;
    }
    else if( n>1 && sqlite3_strnicmp("-groupbyparent", azArg[i], n)==0 ){