9.1 Preparing the Additional Configuration Information File

During synchronization from a relational database to Oracle Internet Directory, the additional configuration information file governs the retrieval of data from the database. It provides the Oracle directory integration and provisioning server with the following information:

The SELECT statement to execute
Either the attribute(s) or the database column(s) to be used in incremental synchronization. Generally, this is either an attribute that contains a timestamp or a change sequence number that the next SQL statement should use to retrieve incremental data.

To configure this file, use the sample file DBReader.cfg.master in the $ORACLE_HOME/ldap/odi/conf directory, and edit it to your specifications.

Formatting the Additional Configuration Information File

It is very important to follow the correct format of this file. The various sections are divided using TAG names. Every TAG section has a list of parameters and their respective values. The general layout is as follows.

[TAG]
PARAMETER1: value
PARAMETER2: value

[TAG]
PARAMETER1: value
PARAMETER2: value\
VALUE continuation\
value continuation\
end of value continuation

[TAG]
PARAMETER1: value
PARAMETER2: value\
end of value continuation

For example, following this format, the DBReader.cfg.master file looks like this:

[DBQUERY]
SELECT: SELECT\

EMPNO EmpNum,\
ENAME,\
REPLACE(EMAIL),'@ACME.COM','') UID,\
EMAIL,\
TELEPHONE,\
TO_CHAR(LAST_UPDATE_DATE,'YYYYMMDDHH24MISS') Modified_Date\

FROM\

EMPLOYEE\

WHERE\

LAST_UPDATE_DATE>TO_DATE (:Modified_Date,'YYYYMMDDHH24MISS')\

ORDER BY\
LAST_UPDATE_DATE

[SYNC-PARAMS]
CHANGEKEYATTRS: Modified_Date

Note that the entire SELECT statement is put as a value in the parameter SELECT in the section represented by the TAG DBQUERY. Because it is a lengthy value, the value continuation character is put as the last character in every line until the SELECT statement ends.

The CHANGEKEYATTRS parameter value is the name of the column(s) to be used while performing incremental synchronization. The value(s) of these column(s) is always stored in the orclOdipLastAppliedChgNum attribute of the profile. Every time the SELECT statement is executed, the current value(s) of this attribute are put into the SQL statement accordingly. This ensures that the data is always retrieved incrementally.

If there are multiple column names in the CHANGEKEYATTRS—for example, column1:column2—then the value in the orclOdipLastAppliedChgNum attribute of the profile is stored as value1~value2 and so on, with value1 corresponding to column1 and value2 to column2.

Column names are retrieved into Directory Integration and Provisioning as attribute value pairs and subsequently mapped into LDAP attribute values according to set mapping rules. For this reason, all columns names retrieved in the SELECT statement must be simple names rather than expressions. For example, you can have the expression REPLACE(EMAIL),'@ACME.COM','') but it retrieves the expression value as UID.

In this example, the Modified_Date is the key for incremental synchronization. Because it is a date, it must be represented in a string format.

When the profile is created, the orclOdipLastAppliedChgNum attribute must be set to some value. All changes after this date—that is, rows in the table with LAST_UPDATE_DATE greater than this value— are retrieved. For example, if the orclOdipLastAppliedChgNum attribute is set to 20000101000000, then all employee changes since January 1, 2000 are retrieved.

Because of the ORDER BY clause, all the database rows returned are in the order of LAST_UPDATE_DATE—that is, the changes retrieved and applied to the directory are in chronological order. Once the last change is retrieved and applied:

The orclOdipLastAppliedChgNum attribute value is set to the Modified_Date from the last row retrieved.
The profile is updated.

Whenever the Directory Integration and Provisioning executes the profile again, it uses the previously stored value.