diff --git a/db/sqlite.go b/db/sqlite.go
index 7985a8f..8474ba1 100644
--- a/db/sqlite.go
+++ b/db/sqlite.go
@@ -14,8 +14,7 @@ func init(){
 }
 
 const migrateScript = `
-alter table blocks add mtime integer default NULL;
-update blocks set mtime = strftime('%s', 'now');
+alter table blocks add mtime integer default 0;
 create index blocks_mtime on blocks(mtime);
 
 CREATE TRIGGER update_blocks_mtime_insert after insert on blocks for each row
@@ -29,6 +28,9 @@ update blocks set mtime = strftime('%s', 'now') where pos = old.pos;
 end;
 `
 
+//TODO: initial run: https://stackoverflow.com/questions/14468586/efficient-paging-in-sqlite-with-millions-of-records
+//TODO: postgres test
+
 type Sqlite3Accessor struct {
 	db *sql.DB
 	filename string