func: static void backend_read_statsfile() if ( pgStatDBHash )  if ( IsAutoVacuumLauncherProcess ( ) )  pgStatDBHash = pgstat_read_statsfile ( MyDatabaseId , ( ( bool ) 0 ) ); static HTAB *pgstat_read_statsfile(Oid onlydb,bool permanent) FILE * fpin ; const char * statfile = ( permanent ? "global/pgstat.stat" : pgstat_stat_filename ) ; if ( ( fpin = AllocateFile ( statfile , "r" ) ) == ( ( void * ) 0 ) )  if ( permanent )  unlink ( "global/pgstat.stat" ); 