DB Discussions: Transaction Model, Savepoints, Locking; Exception Handling; Caching

Transaction Model

TODO Documentation

ChristianK to come up with a general wrapper Class for UIConnectors and WebConnectors which would start and commit/rollback DB Transactions for us (as suggested by ThiasG), relieving programmers of writing code for those tasks over and over.

Savepoints

As of now, we don't use Savepoints in openPETRA.

Investigation

We should do an investigation of whether Savepoints are available.

• Savepoints got generally introduced to .NET with ADO.NET 2.0, but their support is depending on the underlying DB system
• Need to check availability for and perform tests with
  • PostgreSQL
  • MySQL
  • SQLite
  • ODBC in general (for other DB systems without a specific .NET driver)

ChristianK recons we can use Savepoints only

• if they are supported at least with PostgreSQL, MySQL and SQLite
• if they work on Windows and Linux alike.

ChristianK's 'dumping ground' of some initial investigations:

• General
  • [Google Search]
  • [Pro ADO.NET 2.0 book search]
• PostgreSQL
  • [Google Search for Npgsql]
  • [LLBLGenPro documentation]
  • [Google Search for Npgsql savepoint]
  • [Savepoint support is missing (Aug. 2008)]
  • [Npgsql 2 testsuite using Savepoints]

Locking

TODO Documentation

DB Access Exception Handling

TODO Documentation

Maybe utilise the 'general wrapper Class for UIConnectors and WebConnectors' mentioned above to implement general DB Access Exception Handling?

Caching of Data (general)

TODO