tailieunhanh - Managing time in relational databases- P23

Tham khảo tài liệu 'managing time in relational databases- p23', công nghệ thông tin, cơ sở dữ liệu phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 428 THE ASSERTED VERSIONING GLOSSARY The purpose of a staging area is to move the row or rows representing an object into a state where they are not available to normal queries. The reason for doing this is usually to withdraw those rows into an area where a series of updates can be made to them only after which are those rows returned to production data status. external pipeline dataset history table Description this term is generally used to refer to a table of data which contains the before-image copies of production rows which are about to be updated. It is a dataset that exists at the end of a very short outflow pipeline. external pipeline dataset logfile table Mechanics this term is generally used to refer to a table of data which contains the before-image copies of production rows which are about to be inserted updated or deleted. It is a dataset that exists at the end of a very short outflow pipeline. external pipeline dataset query result set Mechanics this term is always used to refer to the results of an SQL query. It is a dataset that exists at the start of an outflow pipeline. external pipeline dataset report Description this term is generally used to refer to a dataset at the end of an outflow pipeline at which point the data can be directly viewed. external pipeline dataset screen Mechanics this term is generally used to refer to a dataset at the end of an outflow pipeline at which point the data can be directly viewed. Comments Aside from the difference in media video display vs. hardcopy screens differ from reports in that reports usually contain data representing many objects while screens usually contain data representing one object or a few objects. fall into currency Mechanics to become a current assertion and or a current version when an assertion and or effective begin date becomes a date in the past. Semantics to become a current assertion and or a currently version because of the passage of time. Comments Once an assertion and or a version