title: sqlite: create a transaction ID for multi-insert transaction
body: <p>I am adding a series of records (eg 100) per single transaction. I want each record to have a 'transaction ID' field, which increments for every new transaction and is the same value for each record inserted within a particular transaction. I want this so clients can perform a query and then at some point in future perform the same query, but only retrieve records with a newer transaction ID. What's the best way of doing it? I don't really want to generate the ID at the application level because the DB is accessed by several processes, so I would then have to coordinate ID allocation cross-process. Or I could have a dedicated TXID table with a single autoincrememt column, insert into that before starting the transaction and use the last_insert_rowid() as the TXID, but it seems a little inefficient to be storing a table of incrementing numbers just to generate IDs. Any thoughts? Thanks.</p>