Define a Schema File - Access Module

Teradata Tools and Utilities Access Modules User Guide

Access Module
Release Number
English (United States)
Last Update
Product Category
Teradata Tools and Utilities

The format of a text file is determined by using a schema information file. This file, named schema.ini, is always kept in the same directory as the text data source, and is required for accessing fixed‑length data. Use a schema.ini file when a text table contains DateTime, Currency, Decimal data, or whenever more control is needed to handle table data.

Create a schema.ini file with entries to specify each of the following five characteristics for the table that needs to be created.

  • Text File Name – The first entry in the schema.ini file must be the name of the text source file enclosed in square brackets.
  • File Format – The file format option specifies how the text file fields are delimited or the length of the fields in a file that uses a fixed length format, as shown in . If used, the file format settings in the schema.ini file override file‑by‑file settings in the Windows Registry.

    Table 18: Schema File Formats 

    Format specifier

    Delimiter Description

    Format statement example

    Tab Delimited

    Fields in the file are delimited by tabs


    CSV Delimited

    Fields in the file are delimited by commas (commaseparated values)


    Custom Delimited

    Fields in the file are delimited by the character specified in the Format statement. All characters are allowed (even the blank character) except the double quote (“)

    Format=Delimited(custom charater)

    Fixed Length

    Fields in the file are a fixed length

  • Field Names, Widths, and Types – Specify the field names in a character‑delimited text file in one the following ways:
  • Set the ColNameHeader to True and include the field names in the first row of the table.
  • For example, the following schema.ini file sets the ColNameHeader to true, keeping the column definitions and names.


    The ColNameHeader setting overrides the FirstRowHasNames setting.

  • Set ColNameHeader to False and specify each column by number and designate the column name, data type, and width for fixed‑length types.
  • For example, the following schema.ini file sets the ColNameHeader to false and redefines the columns.

    Col1=SOR Char Width 255
    Col3=CREATE_DT Date
    Col4=FREETEXT LongChar
    Col5=EOR Char Width 255

    The ColNameHeader setting overrides the FirstRowHasNames setting.

  • Use the MaxScanRows option to indicate how many rows to scan when determining the column types. If MaxScanRows is set to zero, the entire file is scanned.
  • The MaxScanRows setting in the schema.ini file overrides the setting file by file.

  • Use the column number (Coln) option. This option is required for fixed‑length files; it is optional for character‑delimited files.
  • Coln=ColumnName type [width #]

    describes each part of the Coln statement. The following example shows the schema.ini entries for two fields. The fields are specified as the fifth and sixth in the row format, with PartName defined as a text field with a width of ten, and PartNumber also defined as a text field, with a width of 30.

    Col[5]=PartNumber text width[10]
    Col[6]=PartName text width[30]

    Table 19: Coln Statement Parameters 




    Text name of the column. If the column name contains embedded spaces, enclose them in double quotation marks.


    MicroSoft Jet data types:

  • bit
  • byte
  • short
  • long
  • currency
  • single
  • double
  • datetime
  • text
  • memo
  • ODBC data types

  • char (same as text)
  • float (same as double)
  • integer (same as short)
  • longchar (same as memo)
  • date date format
  • width

    Literal string value that specifies the width of the column (required for fixedlength files and optional for characterdelimited files.


    Integer value that designates the width of the column. Required if width is specified.

  • Character Sets – Two character sets are available: ANSI and OEM. This setting overrides the setting in the Windows Registry. The following code sample sets the character set to ANSI:
  • CharacterSet=ANSI

    Note: If any entry is omitted, the default value in the Windows Control Panel is used.

    For more information about the settings in a schema.ini file, go to