Physical Database Design A rule of thumb for choosing indexes for a relational database includes which of the following? Indexes are more useful for columns that do not appear frequently in the WHERE clause in queries. Do not specify a unique index for the primary key of each table. Indexes are more useful on smaller tables. Be careful indexing attributes that have null values. Indexes are more useful for columns that do not appear frequently in the WHERE clause in queries. Do not specify a unique index for the primary key of each table. Indexes are more useful on smaller tables. Be careful indexing attributes that have null values. ANSWER DOWNLOAD EXAMIANS APP
Physical Database Design Hashing algorithm converts a primary key value into a record address. True False True False ANSWER DOWNLOAD EXAMIANS APP
Physical Database Design Sequential retrieval on a primary key for sequential file storage has which of the following features? Slow Impractical Moderately fast Very fast Slow Impractical Moderately fast Very fast ANSWER DOWNLOAD EXAMIANS APP
Physical Database Design A bitmap index is an index on columns from two or more tables that come from the same domain of values. 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 fixed length? NUMBER CHAR LONG VARCHAR2 NUMBER CHAR LONG VARCHAR2 ANSWER DOWNLOAD EXAMIANS APP
Physical Database Design A secondary key is which of the following? Useful for denormalization decisions Nonunique key Determines the tablespace required Primary key Useful for denormalization decisions Nonunique key Determines the tablespace required Primary key ANSWER DOWNLOAD EXAMIANS APP