Teradata Create Table

Introduction to Teradata Create Table

The following article provides an outline for Teradata Create Table. Every sequential database involves the storage of its data in the form of tables. Tables are structures of data which are in row and column format. The columns are vertical entities, whereas the rows are horizontal entities. Here the position in which the row and the columns meet is called a field. Here a table can also be mentioned as an organized collection of the same types of data. The number of rows and tables in a table depends on the space allocated to the table; to create a table in a database, the create table statement is used.

The create table statement is responsible for creating a table in the database. Here Teradata systems also uses the create table statement for the creation of the tables. Teradata more specifically allows the flexibility of allocating the table space or the memory needed for each and every table created more specifically.

Syntax of Teradata Create Table

Given below is the syntax mentioned:

CREATE SET/MULTISET TABLE Name_of_database.Name_of_Table, [NO] FALLBACK
(Name_of_Column#1 Column_Name#1_data_type attribute,
Name_of_Column#2 Column_Name#2_data_type attribute,
Name_of_Column#3 Column_Name#3_data_type attribute,
Name_of_Column#4 Column_Name#4_data_type attribute,
Name_of_Column#N Column_Name#N_data_type attribute)
UNIQUE PRIMARY INDEX (Name_of_Primary_Index_column);

• When SET is mentioned in the table creation, it does not permit duplicate rows; in the MULTISET table, duplicate values are allowed. Here the database name and the table name must be mentioned.
• When a FALLBACK is cited, then the device will generate a replica desk, and this replica desk might be useful when there may be a failure to the device.
• The default fee is NO FALLBACK. For every column in the database, their corresponding column datatypes need to be specified; these data types need to be ensured to match the nature of the column.
• Also, the primary index of the table can be created; here, the column which is expected to be used as the primary index needs to be mentioned in the UNIQUE primary index keyword.

Options in Creating Teradata Tables

There are several options in the ways a table can be created in Teradata; these options are given below:

Examples of Teradata Create Table

Given below are the examples of Teradata Create Table:

Example #1

The first example represents the creation of a SET table, so this table does not allow any duplicate rows. Here 3 columns are created for the table, such as ID, NAME, AGE. Each of these columns is associated with its corresponding data types. The output snaps involve snaps of the table are created, and then the schema of the table is verified. After that, the insert operation is executed on the table. The inserted records are displayed in the snap too.

Code:

CREATE SET TABLE EDUCBA.TEST (ID INTEGER, NAME VARCHAR(50),AGE INTEGER);
INSERT INTO EDUCBA.TEST(ID, NAME, AGE) VALUES (10,’ÁNAND’,34)
INSERT INTO EDUCBA.TEST(ID, NAME, AGE) VALUES (13,’MANJU’,36)
INSERT INTO EDUCBA.TEST(ID, NAME, AGE) VALUES (14,’SAVITHA’,34)
INSERT INTO EDUCBA.TEST(ID, NAME, AGE) VALUES (12,’RAJESH’,34)
SELECT * FROM EDUCBA.TEST;

Output:

Example #2

The first example represents the creation of a MULTISET table, so this allows duplicate rows. Here 5 columns are created for the table, such as ID, NAME, AGE. Each of these columns is associated with its corresponding data types. We can notice from the output file that the insertion of duplicate values in all the columns are comfortably inserted in the table. These duplicate values are printed on to the console, and a snap of the console is captured and attached below. Also, all the insert queries are shared below in the query section.

Code:

CREATE MULTISET TABLE EDUCBA.TEST_MULTI(ID INTEGER, NAME VARCHAR(50),AGE INTEGER);
INSERT INTO EDUCBA.TEST_MULTI (ID, NAME, AGE) VALUES (10,’ÁNAND’,34)
INSERT INTO EDUCBA.TEST_MULTI (ID, NAME, AGE) VALUES (10,’ÁNAND’,34)
INSERT INTO EDUCBA.TEST_MULTI (ID, NAME, AGE) VALUES (10,’ÁNAND’,34)
INSERT INTO EDUCBA.TEST_MULTI (ID, NAME, AGE) VALUES (10,’ÁNAND’,34)
INSERT INTO EDUCBA.TEST_MULTI (ID, NAME, AGE) VALUES (10,’ÁNAND’,34)
SELECT * FROM EDUCBA.MULTI_TEST;

Output:

Conclusion

The create table statement in Teradata systems are very deeply defined such that it is designed to have the capability of formulating tables which can store a solidified amount of data, and also, they have the ability to flexibly mention the memory and index level options for these table items. This is one among the key capabilities that make Teradata among the successful sequential storage-based enterprises around the globe.

Recommended Articles

This is a guide to Teradata Create Table. Here we discuss the introduction, options in creating Teradata tables and examples, respectively. You may also have a look at the following articles to learn more –

1. Teradata data types
2. Collect Stats in Teradata
3. Primary Index in Teradata
4. Teradata Partition by