The Data Integration Service generates a default SQL query that it uses to read data from relational sources. You can override the default query in a customized data object or an instance of a relational data object.
You can override the default query through the simple or advanced query. Use the simple query to select distinct values, enter a source filter, sort ports, or enter a user-defined join. Use the advanced query to create a custom SQL query for reading data from the sources. The custom query overrides the default and simple queries.
If any table name or column name contains a database reserved word, you can create and maintain a reserved words file, reswords.txt. Create the reswords.txt file on any machine the Data Integration Service can access.
When the Data Integration Service runs a mapping, it searches for the reswords.txt file. If the file exists, the Data Integration Service places quotes around matching reserved words when it executes SQL against the database. If you override the default query, you must enclose any database reserved words in quotes.
When the Data Integration Service generates the default query, it delimits table and field names containing the following characters with double quotes: