Replay queries with partially returned results

If a result has been partially sent to the client and the connection is either lost in the middle of it or it ends in a deadlock, the replay is not possible. In certain cases a replay would be possible if the failing result was re-executed and spliced into the existing one.

A simple byte offset into the latest resultset would be a simple but effective method of detecting which parts have been sent to the client and which parts need to match in order for the replay to be safe.

Original description:
SkySQL2 cluster is called customer777-xpand2
Domain Name is dbswf33330813.syss0001.stage1.skysql.net
Database is travel

1. Created database with travel.sql
2. Added primary key with addPrimaryKey.sql
3. In session 1 ran sql script t3a.sql to create a stored procedure
4. In session 1 ran sql script t3arun.sql to run t3a.sql stored procedure
5. In session 2 ran t4.sql to create a stored procedure and run it

The following error was displayed in session 1 after a few minutes

ERROR 1205 (40000) at line 1 in file: 't3arun.sql': [30720] MVCC serializable conflict: This transaction conflicted with a serializable transaction: `travel`.`flights` Primary key: (66773); try restarting transaction