Starting with Oracle Database 12c, Oracle Label Security metadata in the LBACSYS schema can be included when doing a full database export and import operation.

The source database can be Oracle Database 11g release 2 (11.2.0.3), or higher, but the target database must be Oracle Database 12c or higher.

Before starting the Data Pump import on the target database, you must enable Oracle Label Security.

The Data Pump export utility functions in the standard way under Oracle Label Security.

There are, however, a few differences resulting from the enforcement of Oracle Label Security policies.

• For any tables protected by an Oracle Label Security policy, only rows with labels authorized for read access are exported. Unauthorized rows are not included in the export file. Consequently, to export all the data in protected tables, you must have a privilege (such as FULL or READ) that gives you complete access.

• SQL statements to reapply policies are exported along with tables and schemas that are exported. These statements are carried out during import to reapply policies with the same enforcement options as in the original database.

• The HIDE property is not exported. When protected tables are exported, the label columns in those tables are also exported (as numeric values). However, if a label column is hidden, then it is exported as a normal, unhidden column.

• The user must have EXEMPT ACCESS POLICY in order to export all rows in the table, or else no rows are exported.

Oracle Label Security metadata in the LBACSYS schema can be included when you perform a full database export and import operation.

The source database can be Oracle Database 11g release 2 (11.2.0.3), or higher, but the target database must be Oracle Database 12c release 1 (12.1) or higher.

Oracle Data Pump import utility, impdp, automatically imports Label Security metadata including policies, labels, user authorizations, schema and table policy enforcements. You must register and enable Oracle Label Security for the target database before beginning the import operation.

You can use the Oracle Data Pump Import utility functions under Oracle Label Security.

• Requirements for Import Under Oracle Label Security
  You can use the impdp under Oracle Label Security.
• Definition of Data Labels for Import
  The label definitions at the time of import must include all the policy labels used in the export file.
• Imports of Labeled Data Without Installing Oracle Label Security
  When data type for policy label columns is NUMBER, they can be imported into databases that do not have Oracle Label Security installed.
• Imports of Unlabeled Data
  You can import unlabeled data into an existing table protected by an Oracle Label Security policy.
• Importing Tables with Hidden Columns
  A hidden column is exported as a normal column, but the fact that it was hidden is lost.

set serveroutput on
BEGIN
   dbms_output.put_line('BEGIN');
   FOR l IN (SELECT label_tag, label 
                FROM dba_sa_labels
                WHERE policy_name='HR'
                ORDER BY label_tag) LOOP
       dbms_output.put_line
           ('  SA_LABEL_ADMIN.CREATE_LABEL(''HR'', ' ||
            l.label_tag || ', ''' || l.label || ''');');
   END LOOP;
   dbms_output.put_line ('END;');
   dbms_output.put_line ('/');
END;
/

You can use SQL*Loader with the conventional path to load data into a database protected by Oracle Label Security.

Because SQL*Loader performs INSERT operations, all of the standard requirements apply when using SQL*Loader on tables protected by Oracle Label Security policies.

If the policy column for a table is hidden, then you must use the HIDDEN keyword to convey this information to SQL*Loader.

To specify row labels in the input file, you must include the policy label column in the INTO TABLE clause in the control file.

To load policy labels along with the data for each row, you can specify the CHAR_TO_LABEL function or the TO_DATA_LABEL function in the SQL*Loader control file.

Table 15-1 shows the variations that you can use when you load Oracle Label Security data with SQL*Loader.

For example, the following is a valid INTO TABLE clause in a control file that is loading data into the DEPT table:

INTO TABLE dept
(hr_label HIDDEN POSITION (1:22) CHAR "CHAR_TO_LABEL('HR',:hr_label)",
deptno    POSITION (23:26) INTEGER EXTERNAL,
dname     POSITION (27:40) CHAR,
loc       POSITION(41,54)  CHAR)

The following could be an entry in the data file specified by this control file:

HS:FN                  231 ACCOUNTING  REDWOOD SHORES 

You can run the ANALYZE statement on the Oracle Label Security data dictionary tables in the LBACSYS schema.

This enables the cost-based optimizer to improve execution plans on queries, which improves Oracle Label Security performance.

Running ANALYZE on application tables improves the application SQL performance.

Creating the appropriate type of index on the policy label column improves the performance of user-raised queries on protected tables.

If you have applied an Oracle Label Security policy on a database table in a particular schema, then you should compare the number of different labels to the amount of data. Based on this information, you can decide which type of index to create on the policy label column.

• If the cardinality of data in the policy label column (that is, the number of labels compared to the number of rows) is low, then consider creating a bitmapped index.

• If the cardinality of data in the policy label column is high, then consider creating a B-tree index.

Consider the following case, in which the EMP table is protected by an Oracle Label Security policy with the READ_CONTROL enforcement option set, and HR_LABEL is the name of the policy label column. A user raises the following query:

SELECT COUNT (*) FROM SCOTT.EMP;

In this situation, Oracle Label Security adds a predicate based on the label column. For example:

SELECT COUNT (*) FROM SCOTT.EMP
  WHERE hr_label=100;

In this way, Oracle Label Security uses the security label to restrict the rows that are processed, based on the user's authorizations. To improve performance of this query, you could create an index on the HR_LABEL column.

Consider a more complex query (once again, with READ_CONTROL applied to the EMP table):

SELECT COUNT (*) FROM SCOTT.EMP
  WHERE deptno=10

Again, Oracle Label Security adds a predicate based on the label column:

SELECT COUNT (*) FROM SCOTT.EMP
  WHERE deptno=10
  AND hr_label=100;

In this case, you might want to create a composite index based on the DEPTNO and HR_LABEL columns, to improve application performance.

For optimal performance, you can plan a strategy for assigning values to label tags.

In general, it is best to assign higher numeric values to labels with higher sensitivity levels.

This is because, typically, many more users can see data at comparatively low levels and fewer users at higher levels can see many levels of data.

In addition, with READ_CONTROL set, Oracle Label Security generates a predicate that uses a BETWEEN clause to restrict the rows to be processed by the query. As illustrated in the following example, if the higher-sensitivity labels do not have a higher label tag than the lower-sensitivity labels, then the query will potentially examine a larger set of rows. This will affect performance.

Table 15-2 shows a set of label tags assigned as follows:

Here, a user whose maximum authorization is S:A can potentially access data at labels S:A, S, and U:A. Consider what happens when this user raises the following query:

SELECT COUNT (*) FROM SCOTT.EMP

Oracle Label Security adds a predicate that includes a BETWEEN clause (based on the maximum and minimum authorizations) to restrict the set of rows this user can see:

SELECT COUNT (*) FROM SCOTT.EMP
  WHERE hr_label BETWEEN 10 AND 50;

Performance improves, because the query examines only a subset of data based on the user's authorizations. It does not fruitlessly process rows that the user is not authorized to access.

Table 15-3 shows how unnecessary work is performed if the tag values were assigned as follows:

In this case, the user with S:A authorization can see only some of the labels between 100 and 10. Although the user cannot see TS:A,B labels (that is, rows with a label tag of 50). A query would nonetheless pick up and process these rows, even though the user ultimately will not have access to them.

Using a numeric ordering strategy with the numeric label tags applied to the labels can a basis for Oracle Database data partitioning.

Depending on the application, partitioning data based on label values may or may not be useful. Consider, for example, a business-hosting CRM application to which many companies subscribe. In the same EMP table, there might be rows (and labels) for Subscriber 1 and Subscriber 2. That is, information for both companies can be stored in the same table, as long as it is labeled differently. In this case, employees of Subscriber 1 will never need to access data for Subscriber 2, so it might make sense to partition based on label. You could put rows for Subscriber 1 in one partition, and rows for Subscriber2 in a different partition. When a query is raised, it will access only one or the other partition, depending on the label. Performance improves because partitions that are not relevant are not examined by the query.

The following example shows this is done. It places labels in the 2000 series on one partition, labels in the 3000 series on another partition, and labels in the 4000 series on a third partition.

CREATE TABLE EMPLOYEE(
    EMPNO NUMBER(10) CONSTRAINT PK_EMPLOYEE PRIMARY KEY,
    ENAME VARCHAR2(10),
    JOB VARCHAR2(9),
    MGR NUMBER(4),
    HIREDATE DATE,
    SAL NUMBER(7,2),
    COMM NUMBER(7,2),
    DEPTNO NUMBER(4),
    HR_LABEL NUMBER(10))
    TABLESPACE PERF_DATA
    STORAGE (initial 2M
    NEXT 1M
    MINEXTENTS 1
    MAXEXTENTS unlimited)
    PARTITION BY RANGE (hr_label)
    (partition sx1 VALUES LESS THAN (2000) NOLOGGING,
     partition sx2 VALUES LESS THAN (3000),
     partition sx3 VALUES LESS THAN (4000)
 );

When you install Oracle Database Enterprise Edition and Oracle Label Security, an initial Oracle database is created.

If you want to create additional databases, then you should do this using the Database Configuration Assistant. Alternatively, you can create additional databases by following the steps listed in Oracle Database Administrator’s Guide.

Each time you create a new database, you must install the Oracle Label Security data dictionary tables, views, and packages into it, and create the LBACSYS account.

For the first database, this is done automatically when you install Oracle Label Security, regardless of whether or not you choose the custom install. If you do not choose the custom install, then you are installing the database with the label security schema in the seed.

To create additional databases, there are different processes for configuring label security, depending on whether the first database was installed with the custom install or with the label security schema in the seed.

If you initially chose custom install, but did not install label security, you can install and configure label security using either process described in this section.

You can configure Oracle Label Security if the database was installed with the label security schema is in the seed database.

1. Select the Oracle Label Security option in DBCA.
2. Select the check box to configure Oracle Label Security.

You can configure Oracle Label Security after a custom database installation.

1. Connect to the Oracle Database instance as user SYS, using the AS SYSDBA syntax.
2. Run the script $ORACLE_HOME/rdbms/admin/catols.sql.

   This script installs the label-based framework, data dictionary, data types, and packages. After the script is run, the LBACSYS account exists, with the password LBACSYS. All the Oracle Label Security packages exist under this account.

3. Change the default password of the LBACSYS user.

Oracle provides preprocess scripts that perform upgrade and downgrade operations.

As a safety measure, before you run either the upgrade or downgrade preprocess script, Oracle recommends that you back up your audit records. To do this, you can archive the audit trail as described in Oracle Database Security Guide.

Before they run, the preprocess scripts check that there is enough space in the audit tablespace to copy all the audit records, and will exit without processing if there is not.

You may continue running your applications on the database while OLS preprocess scripts are running.

Oracle provides a preprocess script that you must run before you perform an upgrade.

• About Oracle Label Security Upgrades
  You must upgrade Oracle Label Security for pre-Oracle Database 12c release 1 (12.1) databases.
• Running the Oracle Label Security Preprocess Script Before Upgrading
  You can run the Oracle Label Security preprocess script before upgrading.

Oracle provides a preprocess script that you must run before you downgrade.

• About Oracle Label Security Downgrades
  You can downgrade from an Oracle Database 12c release 1 (12.1) or later database that uses Oracle Label Security or Oracle Database Vault.
• Running the Oracle Label Security Preprocess Script Before Downgrading
  You must connect as SYS wth the SYSDBA administrative privilege before running the Oracle Label Security preprocess script for a downgrade.