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undoNextLSN: This field contains the LSN of the next log record that is to be undone for transaction that wrote the last Update Log. Commit Record notes a decision to commit a transaction. Abort Record notes a decision to abort and hence roll back a transaction. Checkpoint Record notes that a checkpoint has been made. These are used to speed up ...
Log-based: Some DAM systems analyze and extract the information from the transaction logs (e.g., the redo logs). These systems use the fact that much of the data is stored within the redo logs and they scrape these logs. Unfortunately, not all of the information that is required is in the redo logs.
In a SQL database, a record is typically called a "row". The introduction of granular (subset) locks creates the possibility for a situation called deadlock. Deadlock is possible when incremental locking (locking one entity, then locking one or more additional entities) is used. To illustrate, if two bank customers asked two clerks to obtain ...
Most database management systems do not document the internal format of their transaction logs, although some provide programmatic interfaces to their transaction logs (for example: Oracle, DB2, SQL/MP, SQL/MX and SQL Server 2008). Other challenges in using transaction logs for change data capture include:
Common Log File System (CLFS) is a general-purpose logging subsystem that is accessible to both kernel-mode as well as user-mode applications for building high-performance transaction logs. It was introduced with Windows Server 2003 R2 and included in later Windows operating systems.
In databases, and transaction processing (transaction management), snapshot isolation is a guarantee that all reads made in a transaction will see a consistent snapshot of the database (in practice it reads the last committed values that existed at the time it started), and the transaction itself will successfully commit only if no updates it has made conflict with any concurrent updates made ...
A transaction is a logical unit of processing delimited by BeginTransaction and CommitTransaction, or Rollback, operations. All updates performed during a transaction are atomic; they either all appear in the database at the same time or none appear. Any subsequent updates by other transactions are invisible to a transaction.
In relational databases, the log trigger or history trigger is a mechanism for automatic recording of information about changes inserting or/and updating or/and deleting rows in a database table. It is a particular technique for change data capturing , and in data warehousing for dealing with slowly changing dimensions .