-------- Original-Nachricht -------- Datum: Wed, 05 Jul 2006 19:30:04 +0100 Von: Nikki Locke <[EMAIL PROTECTED]> An: sqlite-users@sqlite.org Betreff: Re: [sqlite] Multiple Users
> We seem to have a misunderstanding over the definition of "optomistic > locking". Yes, maybe... ;-) > To me, "optimistic" locking means the application doesn't do any locking > when a record is read. All it does it to retain the timestamp of the > record when it was read. I'm oriented to the definitons from OLEDB http://msdn.microsoft.com/library/default.asp?url=/library/en-us/ado270/htm/mdcstlocktypeenum.asp Citation: adLockOptimistic Indicates optimistic locking, record by record. The provider uses optimistic locking, locking records only when you call the Update method. adLockPessimistic Indicates pessimistic locking, record by record. The provider does what is necessary to ensure successful editing of the records, usually by locking records at the data source immediately after editing. > When the application wants to write edited records back to the database, > it does something like... Likewise.... First, if I want to fetch a Record, I allways store a timestamp in combination with the Records-ID and further needed parameters. Then I search for a older Timestamp with exactly equal parameters. If I dont found anyone, I'm the first User with authorisation to change this record. After this any other User can only store a Timestamp it be younger as mine. All Edit-Controls on View are Write-Protected in this case. The Statusline shows a Message, which User is owner of this Record. My Problems are now solved. SQLite performs a physical locking at the DB-File during writing to Disk. Any other Frontend-Instances do wait, until the Writing is ready. The Writer-Frontend release the DB after the succesfully end of the Write-Process. I dont have to do anything... SQlite is a clever DB ;-) Greetings, Anne -- Echte DSL-Flatrate dauerhaft für 0,- Euro*! "Feel free" mit GMX DSL! http://www.gmx.net/de/go/dsl
