(Top 2024/2025 EXAM REVIEW PAPER ) WGU C170 Chapter 5. Exam Review, Rated A+. VERIFIED.

WGU C170 Chapter 5. Exam Review, Rated A+. VERIFIED. 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. database statistics - -In query optimization, measurements about database objects, such as the number of rows in a table, number of disk blocks used, maximum and average row length, number of columns in each row, and number of distinct values in each column. Such statistics provide a snapshot of database characteristics. DBMS performance tuning - -Activities to ensure that clients' requests are addressed as quickly as possible while making optimum use of existing resources. dynamic query optimization - -The process of determining the SQL access strategy at run time, using the most up-to-date information about the database extents - -In a DBMS environment, refers to the ability of data files to expand in size automatically using predefined increments. file group - -See table space. hash index - -An index based on an ordered list of hash values. input/output (I/O) request - -A low-level data access operation that reads or writes data to and from computer devices. manual query optimization - -An operation mode that requires the end user or programmer to define the access path for the execution of a query. manual statistical generation mode - -A mode of generating statistical data access information for query optimization. In this mode, the DBA must periodically run a routine to generate the data access statistics—for example, running the RUNSTAT command in an IBM DB2 database