OPTIMIZING UPDATABLE SCROLLABLE CURSORS IN DATABASE SYSTEMS

摘要

An optimization for updatable scrollable cursors in database systems. To ensure that a temporary copy of a data record matches the data record maintained in the database, th e temporary copy is associated with a timestamp included on each page storing the data records o f the database. The timestamp on a page in the database is updated whenever any record stored on the page is updated. The optimization compares the timestamp stored with the temporary record wit h the current timestamp associated with the page on which the data record is stored in the database. If the two timestamps are matching then the temporary record is identical to the databa se table record and there is no need to carry out a comparison of the attribute values of the temporar y record with the record in the database table.