Oracle

Encrypting network traffic

It is a best practice to encrypt network traffic between the Looker application and your database. Consider one of the options described on the Enabling secure database access documentation page.

If you're interested in using SSL encryption, see the Oracle documentation .

Creating a Looker user

First, create a designated Looker user:

  -- connect / as sysdba; 
 CREATE 
  
 USER 
  
 LOOKER 
  
 IDENTIFIED 
  
 BY 
  
< password 
> DEFAULT 
  
 TABLESPACE 
  
 USERS 
 TEMPORARY 
  
 TABLESPACE 
  
 TEMP 
 ; 
 

Next, give the new Looker user the ability to create sessions:

  GRANT 
  
 CREATE 
  
 SESSION 
  
 TO 
  
 LOOKER 
 ; 
 

Finally, give the Looker user the appropriate SELECT permissions for the data tables that you plan to access from Looker. If you want to access additional tables in the future, you will need to grant SELECT on those new tables as well.

  GRANT 
  
 SELECT 
  
 ON 
  
 -- <all tables that will be used by looker>; 
 

Ensuring Looker can see all tables

Looker may not be able to identify tables (especially empty tables) without first collecting statistics in Oracle. If tables you need do not appear in generated LookML or SQL Runner, try executing:

  EXEC 
  
 DBMS_STATS 
 . 
 GATHER_DATABASE_STATS 
 ; 
 

For alternative methods, consult your Oracle documentation.

Setting up main database objects

Your Oracle DBA must set up the following objects and permissions on Oracle. The following commands create LOOKER_SESSION and LOOKER_SQL as synonyms for V$SESSION and V$SQL .

Run the following commands as the root user to complete this setup. These examples assume that the Looker user's name is LOOKER .

  CREATE 
  
 OR 
  
 REPLACE 
  
 VIEW 
  
 LOOKER_SQL 
 AS 
  
 SELECT 
  
 sql 
 . 
 SQL_ID 
 , 
  
 sql 
 . 
 SQL_TEXT 
  
 FROM 
  
 V$SQL 
  
 sql 
 , 
  
 v$session 
  
 sess 
  
 WHERE 
  
 sess 
 . 
 SQL_ADDRESS 
  
 = 
  
 sql 
 . 
 ADDRESS 
  
 AND 
  
 sess 
 . 
 username 
 = 
 'LOOKER' 
 ; 
 CREATE 
  
 OR 
  
 REPLACE 
  
 SYNONYM 
  
 LOOKER 
 . 
 LOOKER_SQL 
  
 FOR 
  
 LOOKER_SQL 
 ; 
 GRANT 
  
 SELECT 
  
 ON 
  
 LOOKER 
 . 
 LOOKER_SQL 
  
 TO 
  
 LOOKER 
 ; 
 -- Pay special attention to the following comments: 
 -- the following view will be different for clustered Oracle deployments 
 CREATE 
  
 OR 
  
 REPLACE 
  
 VIEW 
  
 LOOKER_SESSION 
 AS 
  
 SELECT 
  
 SID 
 , 
  
 USERNAME 
 , 
  
 TYPE 
 , 
  
 STATUS 
 , 
  
 SQL_ID 
 , 
  
 -- If using a single node Oracle deployment 
  
 "SERIAL#" 
 , 
  
 -- If using a clustered Oracle deployment, like Oracle Real Application Clusters 
  
 ( 
 SERIAL 
 # 
  
 || 
  
 ',' 
  
 || 
  
 INST_ID 
 ) 
  
 AS 
  
 "SERIAL#" 
 , 
  
 AUDSID 
  
 -- If using a single node Oracle deployment 
  
 FROM 
  
 V$SESSION 
  
 -- If using a clustered Oracle deployment, like Oracle Real Application Clusters 
  
 FROM 
  
 GV$SESSION 
  
 WHERE 
  
 USERNAME 
 = 
 'LOOKER' 
 ; 
 CREATE 
  
 OR 
  
 REPLACE 
  
 SYNONYM 
  
 LOOKER 
 . 
 LOOKER_SESSION 
  
 FOR 
  
 LOOKER_SESSION 
 ; 
 GRANT 
  
 SELECT 
  
 ON 
  
 LOOKER 
 . 
 LOOKER_SESSION 
  
 TO 
  
 LOOKER 
 ; 
 

Setting up symmetric aggregates

Your Oracle DBA must set up the LOOKER_HASH function to enable symmetric aggregates . The LOOKER_HASH function is a synonym for the Oracle dbms_crypto.hash function. The DBA must also create the associated synonym and privileges. The following commands assume that the Looker user's name is LOOKER :

  CREATE 
  
 OR 
  
 REPLACE 
  
 FUNCTION 
  
 LOOKER_HASH 
 ( 
 bytes 
  
 raw 
 , 
  
 prec 
  
 number 
 ) 
  
 RETURN 
  
 raw 
  
 AS 
  
 BEGIN 
  
 return 
 ( 
 dbms_crypto 
 . 
 HASH 
 ( 
 bytes 
 , 
  
 prec 
 )); 
  
 END 
 ; 
 CREATE 
  
 OR 
  
 REPLACE 
  
 SYNONYM 
  
 LOOKER 
 . 
 LOOKER_HASH 
  
 FOR 
  
 LOOKER_HASH 
 ; 
 GRANT 
  
 EXECUTE 
  
 ON 
  
 LOOKER 
 . 
 LOOKER_HASH 
  
 TO 
  
 LOOKER 
 ; 
 GRANT 
  
 EXECUTE 
  
 ON 
  
 SYS 
 . 
 LOOKER_HASH 
  
 TO 
  
 LOOKER 
 ; 
 

Depending on your Oracle database configuration, the SYS prefix may be SYSDBA , ADMIN , or unnecessary.

Setting up persistent derived tables

To enable persistent derived tables , give the Looker user the UNLIMITED TABLESPACE and CREATE TABLE permissions. The following commands assume that the Looker user's name is LOOKER :

  GRANT 
  
 UNLIMITED 
  
 TABLESPACE 
  
 TO 
  
 LOOKER 
 ; 
 GRANT 
  
 CREATE 
  
 TABLE 
  
 TO 
  
 LOOKER 
 ; 
 

Setting up query killing

Follow these instructions to configure query killing for either a standard Oracle deployment or an Amazon RDS deployment.

Standard Oracle deployments

To set up query killing in standard Oracle deployments, the Oracle DBA must create the LOOKER_KILL_QUERY procedure as a synonym of ALTER SYSTEM KILL SESSION . To do this, execute the following command:

  CREATE 
  
 OR 
  
 REPLACE 
  
 PROCEDURE 
  
 LOOKER_KILL_QUERY 
 ( 
 p_sid 
  
 in 
  
 varchar2 
 , 
  
 p_serial 
 # 
  
 in 
  
 varchar2 
 ) 
 IS 
  
 cursor_name 
  
 pls_integer 
  
 default 
  
 dbms_sql 
 . 
 open_cursor 
 ; 
  
 ignore 
  
 pls_integer 
 ; 
 BEGIN 
  
 SELECT 
  
 COUNT 
 ( 
 * 
 ) 
  
 INTO 
  
 ignore 
  
 -- If using a single node Oracle deployment 
  
 FROM 
  
 V$SESSION 
  
 -- If using a clustered Oracle deployment, like Oracle Real Application Clusters 
  
 FROM 
  
 GV$SESSION 
  
 WHERE 
  
 username 
  
 = 
  
 USER 
  
 AND 
  
 sid 
  
 = 
  
 p_sid 
  
 -- If using a single node Oracle deployment 
  
 AND 
  
 serial 
 # 
  
 = 
  
 p_serial 
 # 
 ; 
  
 -- If using a clustered Oracle deployment, like Oracle Real Application Clusters 
  
 AND 
  
 ( 
 SERIAL 
 # 
  
 || 
  
 ',' 
  
 || 
  
 INST_ID 
 ) 
  
 = 
  
 p_serial 
 # 
 ; 
  
 IF 
  
 ( 
 ignore 
  
 = 
  
 1 
 ) 
  
 THEN 
  
 dbms_sql 
 . 
 parse 
 ( 
 cursor_name 
 , 
  
 'ALTER SYSTEM KILL SESSION ''' 
  
 || 
  
 p_sid 
  
 || 
  
 ',' 
  
 || 
  
 p_serial 
 # 
  
 || 
  
 '''' 
 , 
  
 dbms_sql 
 . 
 native 
 ); 
  
 ignore 
  
 : 
 = 
  
 dbms_sql 
 . 
 execute 
 ( 
 cursor_name 
 ); 
  
 ELSE 
  
 raise_application_error 
 ( 
 - 
 20001 
 , 
  
 'You do not own session ''' 
  
 || 
  
 p_sid 
  
 || 
  
 ',' 
  
 || 
  
 p_serial 
 # 
  
 || 
  
 '''' 
 ); 
  
 END 
  
 IF 
 ; 
 END 
 ; 
 

The DBA will also need to run these related commands:

  CREATE 
  
 OR 
  
 REPLACE 
  
 SYNONYM 
  
 LOOKER 
 . 
 LOOKER_KILL_QUERY 
  
 FOR 
  
 SYS 
 . 
 LOOKER_KILL_QUERY 
 ; 
 GRANT 
  
 EXECUTE 
  
 ON 
  
 SYS 
 . 
 LOOKER_KILL_QUERY 
  
 TO 
  
 LOOKER 
 ; 
 

Depending on your Oracle database configuration, the SYS prefix may be SYSDBA , ADMIN , or unnecessary.

Amazon RDS deployments

In Amazon RDS Oracle deployments, the rdsadmin.rdsadmin_util.kill procedure is used to kill queries. To use this procedure, the Looker database user must have the DBA role assigned.

Because DBA is an elevated database role, you might consider skipping this step and forgoing query killing in Looker.

To give the Looker database user query killing abilities, run the following command:

  GRANT 
  
 DBA 
  
 TO 
  
 LOOKER 
 ; 
 

Creating the Looker connection to your database

In the Adminsection of Looker, select Connections, and then click Add Connection.

Fill out the connection details. The majority of the settings are common to most database dialects. See the Connecting Looker to your database documentation page for information. The following settings are specific to Oracle:

• Name: Specify the name of the connection. This is how you will refer to the connection in LookML projects.
• Dialect: Oracle.
• Use TNS: Enable Transparent Network Substrate (TNS) connections.
• Host: Hostname or TNS alias.
• Port: Database port.
• Database: Database name (if not using TNS).
• Service Name: Service name (if using TNS).
• Username: Database username or Temp Database if PDTs are enabled.
• Password: Database user password.
• Enable PDTs: Use this toggle to enable persistent derived tables . When PDTs are enabled, the Connectionwindow reveals additional PDT settings and the PDT Overrides section.
• Temp Database : In Oracle a user is a schema , so this should be specified as the name of the database user. For this example, you would use the temp schema value LOOKER .
• Max number of PDT builder connections: Specify the number of possible concurrent PDT builds on this connection. Setting this value too high could negatively impact query times. For more information, see the Connecting Looker to your database documentation page.
• Additional JDBC parameters: Leave this blank, since Oracle does not support additional JDBC parameters.
• Maintenance Schedule: A cron expression that indicates when Looker should check datagroups and persistent derived tables. Read more about this setting in the Maintenance Schedule documentation.
• SSL: Check to use SSL connections.
• Verify SSL: Ignore this field. Oracle will use the default Java Truststore to verify SSL.
• Max connections per node: This setting can be left at the default value initially. Read more about this setting in the Max connections per node section of the Connecting Looker to your databasedocumentation page.
• Connection Pool Timeout: This setting can be left at the default value initially. Read more about this setting in the Connection Pool Timeout section of the Connecting Looker to your databasedocumentation page.
• SQL Runner Precache: To cause SQL Runner not to preload table information and to load table information only when a table is selected, uncheck this option. Read more about this setting in the SQL Runner Precache section of the Connecting Looker to your databasedocumentation page.
• Database Time Zone: Specify the time zone used in the database. Leave this field blank if you do not want time zone conversion. See the Using time zone settings documentation page for more information.

To verify that the connection is successful, click Test. See the Testing database connectivity documentation page for troubleshooting information.

To save these settings, click Connect. In the Adminsection of Looker, select Connections, and then click Add Connection.

Feature support

For Looker to support some features, your database dialect must also support them.

Oracle supports the following features as of Looker 25.10: