摘要:
A method for generating an execution plan for updating and retrieving data from a database in a single process includes: receiving a statement by a server to update a database with a first set of data and to retrieve a second set of data from the database; building a first execution plan to update the database with the first set of data; building a second execution plan to retrieve the second set of data from the database; and building a single execution plan including a combination of the first and second execution plans. The single execution plan allows for the updating and retrieval of data with a single crossing of an interface between a client and the database. By performing both functions in this manner, the efficiency of performing such tasks on the database is significantly increased.
摘要:
A method and system for controlling concurrency of access to data in a database system is provided. The method includes receiving a lock request for access to data in the database system, in which the lock request is a request for a page lock or a row lock for a corresponding row or page in the database system containing the data. The method further includes identifying a partition in the database system that contains the row or the page in the database system containing the data; associating the lock request with a partition lock on the partition that contains the row or the page in the database system containing the data; and accessing the data using the partition lock.
摘要:
Provided is a method for online reorganization and increasing the page size of a DB2 object. A base table and related auxiliary table spaces are reorganized concurrently via a database utility, DB2 REORG utility. The database utility determines which auxiliary tables are related to the base table and automatically includes their respective auxiliary table in the same invocation of the utility. The reorganization is performed via allocated shadow data sets; page size of the allocated shadow data sets is dynamically updated during reorganization. The original data sets are switched with the newly built shadow data sets, and DB2 catalog values and control blocks are updated with new page size values.