Abstract: A log owner of a database system may receive a request from a log tailer of the database system to log a database operation in a transaction log. The log owner maintains the transaction log and the log tailer replays the transaction log. The request includes a record resulting from the database operation, and the record includes lineage information identifying a first previous version of the record observed by the log tailer when generating the record. The log owner then detects whether a record violation has occurred where a second previous version of the record has been committed that is a newer version than the first previous version. In response to detecting that the record violation occurred, the log owner prevents the database operation from being logged in the transaction log and may return an error to the log tailer that pertains to the record violation.

Abstract: Techniques are disclosed that relate to truncating a subrange of records from a database table. A computer system receives a request to truncate the subrange of records. The request specifies a conditional expression that is usable to identify the subrange from other subranges of records of the database table. Before truncating the subrange of records, the computer system determines whether the subrange of records can be truncated from the database table with a single-record subrange truncate operation, regardless of a size of the subrange of records, based on whether the conditional expression satisfies a set of preconditions. Based on determining that the conditional expression satisfies those preconditions, the computer system performs the single-record subrange truncate operation that includes generating a truncate record that causes the subrange of records to be truncated from the database table.

Abstract: Techniques are disclosed that relate to truncating a subrange of records from a database table. A computer system receives a request to truncate the subrange of records. The request specifies a conditional expression that is usable to identify the subrange from other subranges of records of the database table. Before truncating the subrange of records, the computer system determines whether the subrange of records can be truncated from the database table with a single-record subrange truncate operation, regardless of a size of the subrange of records, based on whether the conditional expression satisfies a set of preconditions. Based on determining that the conditional expression satisfies those preconditions, the computer system performs the single-record subrange truncate operation that includes generating a truncate record that causes the subrange of records to be truncated from the database table.