COSC 3380 EXAM 3 QUESTIONS WITH
100% CORRECT ANSWERS
\.How many zeros can appear in a single row of a bitmap index? - ANSWERS✔-
Exactly one
\.Refer to the following scenario:
-A table occupies 1,000 blocks.
-FlightNumber is the primary key.
-An index on FlightNumber occupies 100 blocks.
-The WHERE clause specifies "FlightNumber = 3988."
What is the minimum number of blocks necessary to process the SELECT? -
ANSWERS✔-2
\.Sparse Index - ANSWERS✔-Index on either a unique or non-unique table sort
column.
A sparse index is always on the sort column and contains one entry for each table
block.
\.All of the following are factors considered in costing out a query execution plan
EXCEPT:
-SQL translation time
, -amount of memory needed
-processing time
-number of disk accesses - ANSWERS✔-SQL translation time
\.a cost-based optimizer stores all the following statistics for a table EXCEPT:
- the number of rows in the table
- the number of users authorized to read the table
- the average length of a row
- the amount of unused space per block/page - ANSWERS✔-the number of users
authorized to read the table
\.Table clusters are the most commonly used physical structure for tables. -
ANSWERS✔-False
\.Logical Index - ANSWERS✔-An index with primary key values rather than block
pointers.
\.Primary Index - ANSWERS✔-An index on the primary key of a table. A primary
index is an index on a unique column. Usually, a primary index is on the tables
primary key.
\.A table has a multilevel index with no free space in any index blocks. If the index
is sparse, an insert to the table generates a new index level when the insert
caused a table block split. - ANSWERS✔-True. Since the index is sparse, a new
entry is generated only when the insert causes a table block split.
100% CORRECT ANSWERS
\.How many zeros can appear in a single row of a bitmap index? - ANSWERS✔-
Exactly one
\.Refer to the following scenario:
-A table occupies 1,000 blocks.
-FlightNumber is the primary key.
-An index on FlightNumber occupies 100 blocks.
-The WHERE clause specifies "FlightNumber = 3988."
What is the minimum number of blocks necessary to process the SELECT? -
ANSWERS✔-2
\.Sparse Index - ANSWERS✔-Index on either a unique or non-unique table sort
column.
A sparse index is always on the sort column and contains one entry for each table
block.
\.All of the following are factors considered in costing out a query execution plan
EXCEPT:
-SQL translation time
, -amount of memory needed
-processing time
-number of disk accesses - ANSWERS✔-SQL translation time
\.a cost-based optimizer stores all the following statistics for a table EXCEPT:
- the number of rows in the table
- the number of users authorized to read the table
- the average length of a row
- the amount of unused space per block/page - ANSWERS✔-the number of users
authorized to read the table
\.Table clusters are the most commonly used physical structure for tables. -
ANSWERS✔-False
\.Logical Index - ANSWERS✔-An index with primary key values rather than block
pointers.
\.Primary Index - ANSWERS✔-An index on the primary key of a table. A primary
index is an index on a unique column. Usually, a primary index is on the tables
primary key.
\.A table has a multilevel index with no free space in any index blocks. If the index
is sparse, an insert to the table generates a new index level when the insert
caused a table block split. - ANSWERS✔-True. Since the index is sparse, a new
entry is generated only when the insert causes a table block split.
