Physical Database Design A rule of thumb for choosing indexes for a relational database includes which of the following? Indexes are more useful on smaller tables. Indexes are more useful for columns that do not appear frequently in the WHERE clause in queries. Be careful indexing attributes that have null values. Do not specify a unique index for the primary key of each table. Indexes are more useful on smaller tables. Indexes are more useful for columns that do not appear frequently in the WHERE clause in queries. Be careful indexing attributes that have null values. Do not specify a unique index for the primary key of each table. ANSWER DOWNLOAD EXAMIANS APP
Physical Database Design An extent is a contiguous section of disk storage space. True False True False ANSWER DOWNLOAD EXAMIANS APP
Physical Database Design A field represents each component of a composite attribute. False True False True ANSWER DOWNLOAD EXAMIANS APP
Physical Database Design What is the best data type definition for Oracle when a field is alphanumeric and has a length that can vary? NUMBER LONG VARCHAR2 CHAR NUMBER LONG VARCHAR2 CHAR ANSWER DOWNLOAD EXAMIANS APP
Physical Database Design Which of the following are integrity controls that a DBMS may support? Assume a default value in a field unless a user enters a value for that field. All of these Limit the set of permissible values that a field may assume. Limit the use of null values in some fields. Assume a default value in a field unless a user enters a value for that field. All of these Limit the set of permissible values that a field may assume. Limit the use of null values in some fields. ANSWER DOWNLOAD EXAMIANS APP
Physical Database Design Which of the following improves a query's processing time? Use compatible data types. Query one query within another. Combine a table with itself. Write complex queries. Use compatible data types. Query one query within another. Combine a table with itself. Write complex queries. ANSWER DOWNLOAD EXAMIANS APP