WGU C170 Chapter 5 already passed

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WGU C170 Chapter 5 already passed 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 applic... ation'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 genera [Show More]

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