Configure a self-managed Oracle database

You can configure your self-managed Oracle database to work with the following CDC methods:

Binary log reader (Preview)
LogMiner API

These methods specify how Datastream accesses your log files. For more information about the binary log reader and the LogMiner API, see Work with Oracle database redo log files.

For detailed instructions about how to configure your source Oracle database for each of these methods, see the sections that follow.

Configure your self managed Oracle database for binary log reader

To configure your self-managed Oracle database for use with the binary log reader CDC method, perform the following steps:

Select one of the following methods to access your log files:
- Automatic Storage Management (ASM): if you select this option, you need to create a dedicated ASM connection, and provide its details when you create your connection profile.
- Database directories: if you select this option, you need to create database directory objects that point to the redo log files and the archived log files, and grant READ access to the directories to your database user:
```
CREATE DIRECTORY DIRECTORY_NAME_1 as 'ONLINE_REDO_LOGS_PATH';
CREATE DIRECTORY DIRECTORY_NAME_2 as 'ARCHIVED_REDO_LOGS_PATH';
GRANT READ ON DIRECTORY DIRECTORY_NAME_1 to USER_NAME;
GRANT READ ON DIRECTORY DIRECTORY_NAME_2 to USER_NAME;
```
Replace the following:
- DIRECTORY_NAME_1: the name of the directory for the online redo log files.
- DIRECTORY_NAME_2: the name of the directory for the archived redo log files.
- ONLINE_REDO_LOGS_PATH: the path to the directory where online redo log files are to be stored.
- ARCHIVED_REDO_LOGS_PATH: the path to the directory where archived log files are to be stored.
- USER_NAME: the name of the database user to whom you want to grant READ access.
If you select the binary log reader method and use database directories, you need to provide the redo log and archived log directory names when you create your stream.
Verify that your database is running in ARCHIVELOG mode.

To do so, sign in to your Oracle database and run the following command at the SQL prompt:
SELECT LOG_MODE FROM V$DATABASE;
1. If the result is ARCHIVELOG, then move on to the next step.
2. If the result is NOARCHIVELOG, then you'll need to enable ARCHIVELOG mode for your database.
3. Run the following commands when logged in as SYSDBA:
```
SHUTDOWN IMMEDIATE;
STARTUP MOUNT;
ALTER DATABASE ARCHIVELOG;
ALTER DATABASE OPEN;
```
4. Archived log files consume disk space, so you'll want to configure the DB_RECOVERY_FILE_DEST_SIZE parameter for your database. Use this parameter to specify (in bytes) the hard limit on the total space to be used by target database recovery files. By setting this parameter, you can manage the tradeoff between protecting the database from running out of disk space and the stream failing because of log position loss.
Define a data retention policy for your database by running these Oracle Recovery Manager (RMAN) commands:
```
TARGET /
CONFIGURE RETENTION POLICY TO RECOVERY WINDOW OF 4 DAYS;
```
You use the TARGET / command to start an RMAN client and connect to the source database. See Making Database Connections with RMAN.

We recommend that you retain backups and archive logs for a minimum of 4 days, and 7 days is recommended.

Running this command will restart your database instance so that the changes you made to the database can take effect.
Return to the SQL prompt of the database tool that you're using to configure the Oracle log file rotation policy. We recommend setting a maximum log file size of no more than 512MB.
Enable supplemental log data. To do so, first enable minimal database-level supplemental logging by running the following command:
```
ALTER DATABASE ADD SUPPLEMENTAL LOG DATA;
```
Next, choose whether to turn on logging for specific tables or the entire database.

To log changes only for specific tables, run the following command for each table that you want to replicate:
```
ALTER TABLE SCHEMA.TABLE ADD SUPPLEMENTAL LOG DATA (ALL) COLUMNS;
```
Replace the following:
- SCHEMA: the name of the schema that contains the table.
- TABLE: the name of the table for which you want to log changes.
To replicate most or all tables in your database, consider turning logging on for the entire database. Run the following command to enable supplemental log data for the entire database:
```
ALTER DATABASE ADD SUPPLEMENTAL LOG DATA (ALL) COLUMNS;
```
The supplemental logging mode must be set to ALL. You can't set this mode to PK_ONLY.

Grant the appropriate privileges to the user account that will be used to connect to your database. To do so, run the following commands:

GRANT SELECT ON GV_$LOG TO USER_NAME;
GRANT SELECT ON GV_$LOGFILE TO USER_NAME;
GRANT SELECT ON GV_$ARCHIVED_LOG TO USER_NAME;
GRANT SELECT ON GV_$INSTANCE TO USER_NAME;
GRANT SELECT ON GV_$STANDBY_LOG TO USER_NAME;
GRANT SELECT ON V_$INSTANCE TO USER_NAME;
GRANT SELECT ON V_$PDBS TO USER_NAME;
GRANT SELECT ON V_$TRANSPORTABLE_PLATFORM TO USER_NAME;
GRANT SELECT ON V_$DATABASE TO USER_NAME;
GRANT SELECT ON COL$ TO USER_NAME;
GRANT SELECT ON DBA_OBJECTS TO USER_NAME;
GRANT SELECT ON DBA_TABLESPACES TO USER_NAME;
GRANT SELECT ON DBA_ENCRYPTED_COLUMNS TO USER_NAME;
GRANT SELECT ON DBA_EXTENTS TO USER_NAME;

GRANT CONNECT TO USER_NAME;
GRANT CREATE SESSION TO USER_NAME;
GRANT SELECT ANY TABLE TO USER_NAME;
GRANT READ ON DIRECTORY ONLINELOG_DIR TO USER_NAME;
GRANT READ ON DIRECTORY ARCHIVELOG_DIR TO USER_NAME;

Replace USER_NAME with the name of the user account that you intend to use to connect to your database.

Configure your self managed Oracle database for LogMiner

Verify that your database is running in ARCHIVELOG mode.

To do so, sign in to your Oracle database and run the following command at the SQL prompt:
SELECT LOG_MODE FROM V$DATABASE;
1. If the result is ARCHIVELOG, then move on to step 2.
2. If the result is NOARCHIVELOG, then you'll need to enable ARCHIVELOG mode for your database.
3. Run the following commands when logged in as SYSDBA:
```
SHUTDOWN IMMEDIATE;
STARTUP MOUNT;
ALTER DATABASE ARCHIVELOG;
ALTER DATABASE OPEN;
```
4. Archived log files consume disk space, so you'll want to configure the DB_RECOVERY_FILE_DEST_SIZE parameter for your database. Use this parameter to specify (in bytes) the hard limit on the total space to be used by target database recovery files. By setting this parameter, you can manage the tradeoff between protecting the database from running out of disk space and the stream failing because of log position loss.
Define a data retention policy for your database by running these Oracle Recovery Manager (RMAN) commands:
```
TARGET /
CONFIGURE RETENTION POLICY TO RECOVERY WINDOW OF 4 DAYS;
```
You use the TARGET / command to start an RMAN client and connect to the source database. See Making Database Connections with RMAN.

We recommend that you retain backups and archive logs for a minimum of 4 days, and 7 days is recommended.

Running this command will restart your database instance so that the changes you made to the database can take effect.
Return to the SQL prompt of the database tool that you're using to configure the Oracle log file rotation policy. We recommend setting a maximum log file size of no more than 512MB.
Enable supplemental log data. To do so, first enable minimal database-level supplemental logging by running the following command:
```
ALTER DATABASE ADD SUPPLEMENTAL LOG DATA;
```
Next, choose whether to turn on logging for specific tables or the entire database.

To log changes only for specific tables, run the following command for each table that you want to replicate:
```
ALTER TABLE SCHEMA.TABLE ADD SUPPLEMENTAL LOG DATA (ALL) COLUMNS;
```
Replace the following:
- SCHEMA: the name of the schema that contains the table.
- TABLE: the name of the table for which you want to log changes.
To replicate most or all tables in your database, consider turning logging on for the entire database. Run the following command to enable supplemental log data for the entire database:
```
ALTER DATABASE ADD SUPPLEMENTAL LOG DATA (ALL) COLUMNS;
```
The supplemental logging mode must be set to ALL. You can't set this mode to PK_ONLY.
Grant the appropriate privileges to the user account that will be used to connect to your database. To do so, run the following commands:
```
GRANT EXECUTE_CATALOG_ROLE TO USER_NAME;
GRANT CONNECT TO USER_NAME;
GRANT CREATE SESSION TO USER_NAME;
GRANT SELECT ON SYS.V_$DATABASE TO USER_NAME;
GRANT SELECT ON SYS.V_$ARCHIVED_LOG TO USER_NAME;
GRANT SELECT ON SYS.V_$LOGMNR_CONTENTS TO USER_NAME;
GRANT EXECUTE ON DBMS_LOGMNR TO USER_NAME;
GRANT EXECUTE ON DBMS_LOGMNR_D TO USER_NAME;
GRANT SELECT ANY TRANSACTION TO USER_NAME;
GRANT SELECT ANY TABLE TO USER_NAME;
```
If your organization doesn't permit granting the GRANT SELECT ANY TABLE permission, use the solution described in the Oracle change data capture (CDC) section of the Datastream FAQ page.

If your source database is Oracle 12c or newer, then grant the following additional privilege:
```
GRANT LOGMINING TO USER_NAME;
```
For each command, replace USER_NAME with the name of the user account. Also, running these commands will grant privileges to the user to read from V$DATABASE (which is required for validation), start the log miner, and grant privileges to select from V$LOGMNR_CONTENT.
Grant the user account SELECT access to the DBA_EXTENTS view in your database. This privilege lets you use the ROWID based backfill for your Oracle source:
```
GRANT SELECT ON DBA_EXTENTS TO USER_NAME;
```

What's next

Learn more about how Datastream works with Oracle sources.