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.