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What is the basic purpose of transaction logging?
A transaction log is used to record the fact that a transaction is set to occur as well as the information needed by the database server to recover the data back to a consistent state in event of a sever failure while it is writing information to disk.
What are the characteristics of a transaction?
Transactions have the following characteristics:
- Nested block structure is possible.
- Variables of the native types number , float , boolean and string and arrays of simple types (array of number, array of float, array of boolean, array of string) can be used.
What is the transaction log describe how it works and what it is used for?
A transaction log is a sequential record of all changes made to the database while the actual data is contained in a separate file. The transaction log contains enough information to undo all changes made to the data file as part of any individual transaction.
How to track and log SQL Server stored procedures?
Create a table to log stored procedure activity. Create a procedure in each user database that logs to the central table. Gradually add a call to this logging procedure to the rest of your stored procedures. Aaron Bertrand (@AaronBertrand) is a passionate technologist with industry experience dating back to Classic ASP and SQL Server 6.5.
Why do we need to log from inside a transaction?
It’s nice to log information to a table from stored procedures, triggers, functions and so on. This information helps to understand what has happened during the execution. But if the operation fails, typically the transaction is rolled back so everything written into the database inside this transaction will not be persisted.
What happens when transaction is rolled back in addlogentry?
The problem comes in when stored procedures are called within a transaction, and specifically when they are called from an external application (Like a .NET application making the initial Stored Procedure call). Obviously anything I log using AddLogEntry will be reverted if the transaction rolls back.
Can a CLR procedure be used to log data?
So now we can also use a CLR procedure to log any interesting data. By using either of these mechanisms you can ensure that the information logged during a transaction is persisted even when the transaction is rolled back. This is an enormous benefit from problem solving point of view.