Craig Willey
Quiz by , created more than 1 year ago

College C192 Databases Quiz on C192 / Query Processing, created by Craig Willey on 30/06/2020.

5
0
0
Craig Willey
Created by Craig Willey over 4 years ago
Close

C192 / Query Processing

Question 1 of 10

1

The data cache or ____ is a shared, reserved memory area that stores the most recently accessed data blocks in RAM.

Select one of the following:

  • buffer cache

  • procedure cache

  • SQL cache

  • permanent storage

Explanation

Question 2 of 10

1

If there is no index, the DBMS will perform ____.

Select one of the following:

  • a loop scan

  • a range scan

  • a row ID table access scan

  • a full table scan

Explanation

Question 3 of 10

1

One measure that determines the need for an index is the ____ of the column you want to index. ____ refers to the number of different values a column could possibly have.

Select one of the following:

  • database Statistics

  • data sparsity

  • primary key

  • query optimization

Explanation

Question 4 of 10

1

____ is the central activity during the parsing phase in query processing.

Select one of the following:

  • database Statistics

  • data sparsity

  • SQL query

  • query optimization

Explanation

Question 5 of 10

1

For Optimizer Hints, ____ instructs the optimizer to minimize the overall execution time, that is, to minimize the time it takes to return all rows in the query result set. This hint is generally used for batch mode processes.

Select one of the following:

  • ALL_ROWS

  • FIRST_ROWS

  • INDEX(name)

  • OPTIMIZATION_ROWS

Explanation

Question 6 of 10

1

For Optimizer Hints, ____ instructs the optimizer to minimize the time it takes to process the first set of rows, that is, to minimize the time it takes to return only the first set of rows in the query result set. This hint is generally used for interactive mode processes.

Select one of the following:

  • ALL_ROWS

  • FIRST_ROWS

  • INDEX(name)

  • OPTIMIZATION_ROWS

Explanation

Question 7 of 10

1

The ____ must be set large enough to permit as many data requests to be serviced from cache as possible.

Select one of the following:

  • Data cache

  • SQL cache

  • Sort cache

  • Optimizer mode

Explanation

Question 8 of 10

1

The ____ stores the most recently executed SQL statements (after the SQL statements have been parsed by the optimizer).

Select one of the following:

  • Data cache

  • SQL cache

  • Sort cache

  • Optimizer mode

Explanation

Question 9 of 10

1

The ____ is used as a temporary storage area for ORDER BY or GROUP BY operations, as well as for in-dex-creation functions.

Select one of the following:

  • Data cache

  • SQL cache

  • Sort cache

  • Optimizer mode

Explanation

Question 10 of 10

1

Most DBMSs operate in one of two optimization modes: cost-based or rule-based. Others automatically de-termine the ____ based on whether database statistics are available.

Select one of the following:

  • Data cache

  • SQL cache

  • Sort cache

  • Optimization mode

Explanation