Installation steps

Steps:

• Download and install a version of Oracle Database. For example Oracle Express.
• Download the corresponding Oracle JDBC Drivers and copy the JAR (e.g. ojdbc6.jar in WEB-INF/lib/)
• Start Oracle and connect to it with a DBA or system user. For example use the Oracle SQL*Plus command-line tool: connect system;
• Create the wiki user and schema:
  create user xwiki
  identified by xwiki;
• Create a tablespace (which is the Oracle term for what you know as a "database" on Microsoft SQL Server):
  select *
  from   dba_data_files
  ;
  --
  -- Pick an adequate name from the list above.
  --
  create tablespace xwiki
  datafile '/opt/SOMETHING/oracle/oradata/SID/xwiki01.dbf'
  size 1m
  autoextend on
  maxsize 1g
  ;
• Create tables of the xwiki user by default in the new tablespace:
  alter user xwiki
  default tablespace xwiki
  temporary tablespace temp
  ;
  alter user xwiki quota unlimited on xwiki
  ;
• Give sufficient privileges to the xwiki user:
  grant create session to xwiki;
  grant create table to xwiki;
  grant create sequence to xwiki;
• Tell XWiki to use Oracle. To do this, edit the WEB-INF/hibernate.cfg.xml file where you have expanded the XWiki WAR file and uncommented the Oracle part. Make sure to review the connection.url property. For example a typical Oracle Express would be:<property name="connection.url">jdbc:oracle:thin:@localhost:1521:XE</property>

  XE is the default name of the ORACLE SID created by default by the installation for Oracle Express. If it is another you should change it. You can find the correct SID in app/oracle/product/10.2.0/server/NETWORK/ADMIN/tnsnames.ora in the Oracle installation directory (for Windows).

Troubleshooting

ORA-01400: cannot insert NULL into ("XWIKI"."XWIKILARGESTRINGS"."XWL_ID")

This error can appear if you're using Oracle JDBC driver 10.2.0.1.0. The solution is to use version 10.2.0.2 or greater of the driver.

SetString can only process strings of less than 32766 chararacters

If you see an error that says something like this:

Then that's because Oracle has a limitation of 32K for CLOBs. To overcome it you need to add the following 2 properties in the hibernate.cfg.xml file, as specified in the installation steps section above: