Lesson 5: Indexes (FLASH CARDS) - C170 - Database Management Applications (WGU)

access plan - A set of instructions generated at application compilation time that is created and managed by a DBMS. The access plan predetermines how an application's query will access the database at run time. algorithms - A process or set of operations in a calculation. automatic query optimization - A method by which a DBMS finds the most efficient access path for the execution of a query. B-tree index - An ordered data structure organized as an upside-down tree. bitmap index - An index that uses a bit array (0s and 1s) to represent the existence of a value or condition. buffer cache - See data cache. data cache - A shared, reserved memory area that stores the most recently accessed data blocks in RAM. Also called buffer cache. data files - A named physical storage space that stores a database's data. It can reside in a different directory on a hard disk or on one or more hard disks. All data in a database is stored in data files. A typical enterprise database is normally composed of several data files. A data file can contain rows from one or more tables. data sparsity - A column distribution of values or the number of different values a column can have. database performance tuning - A set of activities and procedures designed to reduce the response time of a database system—that is, to ensure that an end-user query is processed by the DBMS in the minimum amount of time.