> Sorry, I don't quite understand. Would implementing GAE transactions > result in a change to how we call on the DAL?
Yes. The proposal mentioned above is explained here: http://groups.google.com/group/web2py/browse_thread/thread/293fe4c58ffe8c87/932bc293ba7dbfe6?hl=en&lnk=gst&q=dal+transaction#932bc293ba7dbfe6 We can provide both notations: 1) row.update_record(count=db.table.count+1) 2) row.update_record(count=lambda r: r.count+1) db.table.count+1 and lambda r: r.count+1 is nice syntax for atomically updating a single record, but it does not make it easy for the application handle transaction failures in a cross driver way. Also if you want access to the full power of appengine transactions which is required to create locks, create_or_insert/unique-constraints, create/read/update/delete other records in the same entity group, it should not be done in an update_record lamda. To get the full power of appengine transactions, you would need: txn = db.build_transaction(mytxn) which allows you to create/read/update/delete other records in the same entity group and handle transaction failures in a consistent way. Robin > P.S. the more I work with Google Big Table, the more I'm finding it > very crippled... (and crippling in terms of development difficulty) It might feel like more difficultly up front, but you gain complete scalability, so you do not have to rewrite things later on to scale. If you want to experience real development difficulty, you could try designing/configuring/operating a multi-master relational database, now that is painful! ;) Robin On Jan 18, 8:11 am, Jonathan Benn <[email protected]> wrote: > Hi Robin, > > On Jan 18, 3:30 pm, Robin B <[email protected]> wrote: > > > Calling the txn(...) returns whether the txn suceeded or failed, so > > you do not have to handle any custom exceptions outside the dal. For > > SQLDB the txn(...) will allways return True. > > Sorry, I don't quite understand. Would implementing GAE transactions > result in a change to how we call on the DAL? > > P.S. the more I work with Google Big Table, the more I'm finding it > very crippled... (and crippling in terms of development difficulty) > > --Jonathan --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "web2py Web Framework" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/web2py?hl=en -~----------~----~----~----~------~----~------~--~---
