0

databases Online Quiz - 62

Description: databases Online Quiz - 62
Number of Questions: 20
Created by:
Tags: databases
Attempted 0/20 Correct 0 Score 0

What is the result of a full table scan occurring on Teradata? (Choose two)

  1. All data rows are copied into temporary space

  2. Each data block for a table is read

  3. Each data row is accessed only one

  4. A random set of data blocks for a table is read


Correct Option: B,C

Of the following which is a true statement with regard to a primary index operation?

  1. When choosing a primary index you should pick a column with a severely limited value set

  2. If distribution is skewed an all-AMP operation will take longer than if all AMPs were evenly utilized

  3. Selecting a NUPI for storing data provides for maximum efficiency and makes the best use of the parallel features of Teradata

  4. The degree of uniqueness is not critical ot efficiency.


Correct Option: B

AI Explanation

To answer this question, let's go through each option to understand why it is correct or incorrect:

Option A) When choosing a primary index, you should pick a column with a severely limited value set.

  • This option is incorrect. When choosing a primary index, it is generally recommended to pick a column with a broad value set to evenly distribute data across AMPs and optimize performance.

Option B) If distribution is skewed, an all-AMP operation will take longer than if all AMPs were evenly utilized.

  • This option is correct. In Teradata, data distribution across AMPs plays a crucial role in achieving optimal performance. If the data distribution is skewed, meaning that some AMPs have significantly more data than others, an all-AMP operation will take longer as the workload is not evenly distributed.

Option C) Selecting a NUPI for storing data provides for maximum efficiency and makes the best use of the parallel features of Teradata.

  • This option is incorrect. While selecting a NUPI (Non-Unique Primary Index) can provide some benefits in certain scenarios, it does not necessarily guarantee maximum efficiency or the best use of parallel features. The choice of primary index depends on various factors such as data distribution, workload, and query patterns.

Option D) The degree of uniqueness is not critical to efficiency.

  • This option is incorrect. The degree of uniqueness in a primary index is critical to efficiency in Teradata. A highly unique primary index distributes the data evenly across AMPs, allowing for efficient parallel processing. On the other hand, a low degree of uniqueness can lead to skewed data distribution and inefficient query performance.

The correct answer is B) If distribution is skewed, an all-AMP operation will take longer than if all AMPs were evenly utilized. This option is correct because skewed data distribution can lead to imbalanced workloads and slower performance in Teradata.

Which are two exclusive features of Teradata? (Choose two)

  1. Mature optimizer

  2. Industry standard access language(SQL)

  3. Concurrent users

  4. Parallel architecture


Correct Option: A,D

Queries based on set threshold are restricted by which tool?

  1. Teradata Manager

  2. BTEQ

  3. Teradata SQL Assistant

  4. TDQM


Correct Option: D

You are an administrator at CertKiller.com. CertKiller.com has a Teradata system with 100 GB of permanent space, of which 50 GB is reserved for spool space. The system currently has 30 GB of user data. What is the total available spool space for user queries?

  1. 70 GB

  2. 50GB

  3. 30 GB

  4. 80 GB


Correct Option: A

AI Explanation

To calculate the total available spool space for user queries, we need to subtract the amount of user data from the reserved spool space.

Given information:

  • Total permanent space = 100 GB
  • Reserved spool space = 50 GB
  • Current user data = 30 GB

To calculate the available spool space, we subtract the current user data from the reserved spool space: Available spool space = Reserved spool space - Current user data

Substituting the given values: Available spool space = 50 GB - 30 GB Available spool space = 20 GB

Therefore, the total available spool space for user queries is 20 GB.

In which way is data distributed with a Partitioned Primary Index?

  1. It is based on the Secondary Index

  2. It is based on the primary key of the table

  3. It is on the partitioning column

  4. It is based on the Primary Index of the table


Correct Option: D

A Partitioned Primary Index should be used for what two reasons? (Choose two)

  1. It is the Primary Key of the table, which guarantees uniqueness

  2. It allows instantaneous dropping of old data and rapid addition of new data

  3. It avoids full table scans without the overhead of a secondary index.

  4. It places all data in a specific range on the same AMP.


Correct Option: C,D
  1. creating a report to show a comparison of sales from this week to last week

  2. creating a report show how much credit can be extended to a customer

  3. creating a report that shows the top ten selling items across all stores for one year

  4. updating a checking account to reflect a deposit


Correct Option: D

You are an administrator at CertKiller.com. CertKiller.com has a Teradata system with 100 GB of permanent space and creates User A with 30 GB permanent space. How much spaces will User A have, if User A creates User B with 20 GB permanent space?

  1. 70GB

  2. 80GB

  3. 10GB

  4. 30GB


Correct Option: C

When utilizing a unique secondary index, how may AMP (s) is usually accessed?

  1. All-AMP

  2. One-AMP

  3. Multi-AMP

  4. Two-AMP


Correct Option: D

How would you define a transaction?

  1. A logon, submittal of work, and logoff

  2. A single sql statement

  3. A logical unit or work

  4. A single sql, statement and the unit of recovery


Correct Option: C

Consider the emp table having columns empno, ename Which of the following SQL query fetches empno that occur more than twice in the emp table.

  1. select count() from emp group by empno having count() >2;

  2. select empno, count() from emp having count() >2;

  3. select empno, count() from emp where count() >2;

  4. select empno, count() from emp group by empno having count() >2;


Correct Option: D

In a database row is also called as

  1. Query

  2. Attribute

  3. Relation

  4. Record


Correct Option: D

which of the following denote single value function used in SQL

  1. AVG ( )

  2. SQRT ( )

  3. COUNT ( )

  4. All the Above


Correct Option: B

While creating tables the concept that is used to reduce redundancy in data is called

  1. Views

  2. Aliases

  3. Sequence

  4. Normalization


Correct Option: D

A table T1 having 100 rows is joined with a table T2 with 50 rows without specifying the joined column in the where clause then result will have

  1. 100 rows

  2. 50 rows

  3. 150 rows

  4. 5000 rows


Correct Option: D

Which isolation level doesn't exists

  1. Isolation level2

  2. Isolation level3

  3. Isolation level4

  4. Isolation level1


Correct Option: C

Which normal forms require that non-key columns be functionally dependent solely on the primary key?

  1. Second

  2. Fifth

  3. Third

  4. None of above


Correct Option: C

Which of the following options is FALSE about unchained mode in ASE

  1. A commit tran is always implied for every transaction.

  2. Unchained mode is the default mode in ASE

  3. The server does not issue the begin tran implicity

  4. The value of @@tranchained is 0


Correct Option: A
- Hide questions