Global Attributes refactor for write operation(execute/RPC API)

[longquanzheng]

1. support multi rows
2. Postgres doesn't have a single upsert command. We need to change setXXX semantic from upsert to update, requiring all rows are present , return error if not.
3. for now limits the error handling to always error+retry on update fails at conflict(e.g. unique constraint). In the future, we may support more options, like DO NOTHING or set update etc.
4. in the future also support insert mode
5. in the future we can even support upsert mode -- using multiple SQL command in Postgres