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About Columns and Indexes in a Siebel Table

A column is a representation of the physical column that resides in the underlying database management system. The Siebel schema records the name, data type, length, primary key status, foreign key status, alias, and other properties of the database column as properties in the corresponding object definition of the column. The schema includes other properties that are internal to Siebel CRM in the object definition, such as the Changed status, Inactive status, and the Type. For more information, see the following topics:

• Properties of a Table Column
• How a CIAI Index Can Improve a Query.

Data Columns of a Siebel Table

A data column is a column that provides data for a field. It can serve as a foreign key that references a row in another table. Most columns in Siebel CRM are data columns. A data column is sometimes referred to as a base column. A data column can be public or private. You cannot modify the properties of a data column.

Extension Columns of a Siebel Table

An extension column is a column that stores custom data. Siebel CRM supports the following types of extension columns:

• Predefined extension column. Included in a predefined extension table. Siebel CRM names these columns ATTRIB_nn, where nn is a value between 01 and 47. For example, ATTRIB_13. It is recommended that you do not modify or delete a predefined extension column.
• Custom extension column in an extension table. Added by a developer to an extension table. Siebel CRM names these with an X_ prefix.
• Custom extension columns in a base table. Added by a developer to a base table. The relational database system that you use with Siebel CRM determines if this configuration is allowed or not allowed. If the database system supports a custom extension column in a base table, it might be preferable for performance reasons to add it to the base table rather than to add it to an extension table. Performance might be affected if you add an extension column to an extension table because Siebel CRM creates extra SQL to join the extension table.

System Columns of a Siebel Table

A system column is a column that Siebel CRM displays in all tables, but it does not include the same set of system columns in every table. You can use the data in a system column for various reasons. For example, you can use the ROW_ID column to create a join. Most system columns are read-only. You typically must not modify the data in a system column. Some exceptions exist, such as using certain system columns in an interface table. For more information, see System Fields of a Business Component.

Table 9 describes some of the system columns that Siebel CRM commonly uses.

Siebel CRM updates the following columns:

• CREATED
• CREATED_BY
• LAST_UPD
• LAST_UPD_BY
• ROW_ID

The following columns store the date, time, and user values for the client. They do not store the date, time, and user values for the Siebel database:

• CREATED
• CREATED_BY
• LAST_UPD
• LAST_UPD_BY

Indexes of a Siebel Table

An index is a logical representation of a physical index that resides in the underlying database management system. Siebel CRM includes a set of predefined indexes. The name for each index contains an S_ prefix. You must not modify or delete a predefined index. You can create a custom index. For more information, see Properties of an Index of a Siebel Table and Creating a Custom Index.

Index Columns of an Index

An index column is a child object of the index object. The object definition for an index column associates one column to the parent index. For more information, see Properties of an Index Column and Creating a Custom Index.