Appendix A Type and Format Differences Between Teradata and Other DBMS . Teradata 2580

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APPENDIX A

Type and Format Differences

Between Teradata and Other DBMS

This appendix describes the differences between the types and formats used in Teradata and those used in other database management systems, such as Oracle.

Teradata Data Types

The data types supported in Teradata Database may differ from the data types in other ANSIcompliant databases. Therefore, you need to convert your data types to Teradata data types.

Be aware that even though some data types seem the same in both systems, there may be subtle differences in the way the data types are implemented. Therefore, your query may not return an error, but the results may not be as expected.

Recommendation: Always test your queries thoroughly after converting to Teradata and make sure that the data type functions as you expect.

The following table shows how some Oracle data types can be mapped to Teradata data types:

Oracle Data Type

BLOB/CLOB

CHAR

DATE

FLOAT

LONG

LONG RAW

NUMBER or NUMBER(38)

NUMBER(m, n)

VARCHAR2

Teradata Data Type

BLOB/CLOB

CHAR

DATE or TIMESTAMP(0)

FLOAT

(The total number of digits cannot exceed 15)

LONG VARCHAR or VARCHAR

VARBYTE (<=64000)

DECIMAL(38)

DECIMAL(m, n)

VARCHAR

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Appendix A: Type and Format Differences Between Teradata and Other DBMS

Teradata Data Types

In Teradata, the maximum number of characters or bytes allotted to a CHAR or VARCHAR column depends on the server character set for the column. For example, if the server character set is:

•

LATIN, then the maximum value is 64,000

•

UNICODE, then the maximum value is 32,000

For Oracle users, note that Oracle does not have an INTEGER data type, but they have an alias called INTEGER that maps to the NUMBER data type. NUMBER corresponds to the

DECIMAL data type in Teradata. Teradata has several additional numeric data types, including:

•

BYTEINT - a signed binary integer value from -128 to 127

•

SMALLINT - a signed binary integer value from -32,768 to 32,767

•

INTEGER - a signed, binary integer value from -2,147,483,648 to 2,147,483,647

•

BIGINT - a signed, binary integer value from -9,223,372,036,854,775,808 to

9,223,372,036,854,775,807

The following table shows additional possibilities for converting the NUMBER data type.

Oracle Data Type

NUMBER(1)

NUMBER(2,n)

NUMBER(3)

NUMBER(4,n)

NUMBER(5)

NUMBER(9,n)

NUMBER(10)

NUMBER(18)

NUMBER(19,n)

NUMBER(38,n)

Teradata Data Type

BYTEINT - 8 bits or

DECIMAL(1) - 8 bits

DECIMAL(2,n) - 8 bits

BYTEINT - 8 bits or

SMALLINT - 16 bits or

DECIMAL(3) - 16 bits

DECIMAL(4,n) - 16 bits

SMALLINT - 16 bits or

INTEGER - 32 bits or

DECIMAL(5) - 32 bits

DECIMAL(9,n) - 32 bits

INTEGER - 32 bits or

DECIMAL(10) - 64 bits

BIGINT - 64 bits or

DECIMAL(18) - 64 bits

DECIMAL(19,n) - 128 bits

DECIMAL(38,n) - 128 bits

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Appendix A: Type and Format Differences Between Teradata and Other DBMS

Teradata Data Types

DATE Formats

In Teradata, the date format for the system is set with the DateForm configuration setting and the default date format setting in the specification for data formatting (SDF) file.

Those settings determine the following:

•

Export data type of DATE values

•

Data entry format for DATE values

•

Format of DATE values in macros being executed

•

Date format for string-to-DATE comparisons and conversions

•

Display format of DATE columns in newly created tables and views

You can use the DBS Control utility (dbscontrol) to set DateForm to the following:

Setting

0 (IntegerDate)

1 (ANSIDate)

Description

Use the system default DATE format specified in the SDF file.

The default format is YY/MM/DD. However, you can customize the SDF file to change this date format to any valid date format.

The export data type is four-byte integer.

The system default DATE format is YYYY-MM-DD.

The export data type is CHARACTER(10).

This format is similar to the DATE data type format in Oracle.

Initially, DateForm is set to IntegerDate. You can override the system-level date format for a user, session, individual DATE column or DATE value.

To change the DATE format setting for ...

the system the session a user a DATE column or DATE value

Use the ...

•

DBS Control utility to change the DateForm setting.

•

Locale Definition utility (tdlocaledef) to customize the SDF file.

SET SESSION DATEFORM statement.

DATEFORM option in the CREATE USER or

MODIFY USER statement.

FORMAT phrase.

To view the current value of the system default DATE format, enter:

HELP SESSION;

Recommendation: To avoid format errors in date operations, specify dates as ANSI DATE literals. All SQL date operations accept this format. The format for an ANSI DATE literal is:

DATE 'YYYY-MM-DD'

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Appendix A: Type and Format Differences Between Teradata and Other DBMS

Teradata Data Types

Geospatial Types

Teradata Database supports geospatial types. Geospatial information identifies the geographic location of features and boundaries on the planet. Geospatial types address the need to store, manage, retrieve, manipulate, and analyze geospatial information by governmental bodies and commercial enterprises. For example, local governments might use geospatial data for city planning, traffic management, or accident investigation.

You can use geospatial types to represent 0-dimensional (point), 1-dimensional (line), and 2dimensional (polygon) geometries.

Teradata Database implements geospatial types as system-defined structured types. The geospatial types define methods that perform geometric calculations and test for spatial relationships between two geospatial values.

User-Defined Types

Teradata Database supports user-defined types (UDTs). SQL provides a set of predefined data types, such as INTEGER and VARCHAR, that you can use to store the data that your application uses, but they might not satisfy all of the requirements you have to model your data.

User-defined types allow you to extend SQL by creating your own data types and then using them like predefined data types. You can also define methods that operate on the UDT.

Distinct Types

Distinct UDTs are based on a single predefined data type, such as INTEGER or VARCHAR.

For example, you can create a distinct UDT named euro that is based on a DECIMAL(8,2) data type and use it to store monetary data. You can define a method for the euro type that converts the value to a US dollar amount.

Structured Types

Structured UDTs are collections of one or more fields called attributes, each of which is defined as a predefined data type or other UDT (which allows nesting).

For example, you can create a structured UDT named circle that consists of x-coordinate, y-coordinate, and radius attributes. You can define a method for the circle type that computes the area of the circle using the radius attribute.

Note: Teradata has different storage definition requirements than Oracle and does not use extents or table spaces.

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Appendix A: Type and Format Differences Between Teradata and Other DBMS

Reference Information

Information on...

supported data types in Teradata Database, including UDTs geospatial types

DATE literals

DATE formats and the FORMAT phrase

Is available in...

Chapter 3: “Decimal/Numeric Data Types”SQL Data

Types and Literals

Chapter 2: “Types” in SQL Geospatial Types,