Teradata Multiset Vs Set Table – Where Is The Difference – Cool Example – Check In 5 Mins!

Teradata multiset vs set table - where is the difference - cool example - check in 5 mins?
Share this post and Earn Free Points!

In this short post you will find out what is the difference between the SET and MULTISET table (Teradata" multiset vs set table) and why you need to know the difference before creating your table.

Introduction

Teradata

Teradata" is a company that provides data warehousing and business intelligence solutions. Its products and services are designed to help organizations manage, analyze, and leverage their data to make informed decisions.

Some key features of Teradata" products include:

  • Scalability: Teradata" systems can handle very large volumes of data and support concurrent access from multiple users.
  • Performance: Teradata" systems are optimized for fast query processing and can handle complex queries and data manipulation tasks.
  • Integration: Teradata" products can be integrated with a variety of other systems and tools, such as business intelligence platforms and big data" analytics tools.
  • Security: Teradata" systems offer robust security features, including data encryption and access controls, to protect sensitive data.

Teradata" products are used by a wide range of organizations, including Fortune 500 companies, government agencies, and healthcare organizations. They are particularly well-suited for organizations that have large and complex data sets, and need to perform fast and accurate analytics on that data.

Teradata Set Vs Multiset

In Teradata", a set table is a type of table that does not allow duplicate rows. This means that if you try to insert a row into a set table that is already present in the table, the insert operation will fail.

A multiset table, on the other hand, allows duplicate rows. This means that you can insert multiple copies of the same row into a multiset table.

Set and multiset tables have different implications for data integrity and performance. Set tables can be faster to query, because they do not have to handle duplicate rows. They can also be more efficient in terms of storage, because they do not have to store multiple copies of the same data. However, set tables can be more restrictive, because they do not allow duplicate rows.

Multiset tables, on the other hand, are more flexible, because they allow duplicate rows. However, they can be slower to query and less efficient in terms of storage, because they have to handle duplicate data.

Which type of table you should use depends on your specific requirements and the nature of your data. You should consider factors such as the volume and complexity of your data, the types of queries you will be running, and the performance and storage requirements of your application.

Teradata Multiset Vs Set Table

SET TABLE

The tables defined as SET primarily do not allow you store duplicate data. Teradata" will also not allow you to create this type of table by defining it as NO PRIMARY INDEX". Let’s look at the following example:

CREATE SET TABLE STUDY (
STUDY_ID INTEGER,
STUDY_NAME VARCHAR(10),
STUDY_STATUS BYTEINT);

INSERT INTO STUDY VALUES (1,'XYZ', 0);

Ok, we created the tables and put the first record in it. Let’s try to add a duplicate:

INSERT INTO STUDY VALUES (1,'XYZ', 0);

At this point you probably got the error “Duplicate row error in STUDY”. Duplicates in this table are not allowed! (Teradata" multiset vs set table)

MULTISET TABLE

MULTISET tables allow you to store duplicates. Let’s define COUNTRY tables this time as MULTISET tables:

CREATE MULTISET TABLE COUNTRY (
COUNTRY_ID INTEGER,
COUNTRY_NAME VARCHAR(50),
COUNTRY_CODE VARCHAR(2));

INSERT INTO COUNTRY VALUES (1,'POLAND', 'PL');

And now let’s try to add a duplicate:

INSERT INTO COUNTRY VALUES (1,'POLAND', 'PL');

Table Type And Performance Impact

If you define your table as SET, every time you insert or update the data, Teradata checks it for duplicates. For small tables, this does not matter, but if the tables contain a lot of data, these operations will take much more time than the same operations on the MULTISET table.

In general, set tables tend to be faster to query than multiset tables, because they do not have to handle duplicate rows. This is because the database" engine can stop searching for additional rows once it finds a match in a set table, whereas it has to continue searching through all the duplicate rows in a multiset table to find all the matches.

Set tables can also be more efficient in terms of storage, because they do not have to store multiple copies of the same data. This can make them more suitable for large and complex data sets, where storage efficiency is a concern.

Multiset tables, on the other hand, are more flexible, because they allow duplicate rows. However, they can be slower to query and less efficient in terms of storage, because they have to handle duplicate data.

Which type of table you should use depends on your specific requirements and the nature of your data. You should consider factors such as the volume and complexity of your data, the types of queries you will be running, and the performance and storage requirements of your application. In general, set tables may be more suitable for scenarios where query performance and storage efficiency are important, while multiset tables may be more suitable for scenarios where flexibility and the ability to store duplicate rows is important.

Okay, but what if I want my table to store unique data?

The best answer to this question will be the unique primary index" (UPI).

Summary

In Teradata", a set table is a type of table that does not allow duplicate rows, while a multiset table allows duplicate rows.

Set tables tend to be faster to query and more efficient in terms of storage, because they do not have to handle duplicate rows or store multiple copies of the same data. They can be more suitable for large and complex data sets, where query performance and storage efficiency are important.

Multiset tables, on the other hand, are more flexible, because they allow duplicate rows. However, they can be slower to query and less efficient in terms of storage, because they have to handle duplicate data. They may be more suitable for scenarios where the ability to store duplicate rows is important.

Could You Please Share This Post? 
I appreciate It And Thank YOU! :)
Have A Nice Day!

How useful was this post?

Click on a star to rate it!

Average rating 4.8 / 5. Vote count: 540

No votes so far! Be the first to rate this post.

As you found this post useful...

Follow us on social media!

We are sorry that this post was not useful for you!

Let us improve this post!

Tell us how we can improve this post?