1.9i Oracle Official Documentation
1) Online Browsing
Http://www.oracle.com/pls/db92/homepage
2) Download in hand, refer to worry-free
Oracle9i Database Release 1 (9.0.1) documentation
Http://www.oracle.com/technology/documentation/Oracle9i_arch_901.html
Oracle9i Database Release 2 (9.2) Documentation
Http://www.oracle.com/technology/documentation/oracle9i.html
2.10g Oracle Official Documentation
1) Online Browsing
Http://www.oracle.com/pls/db102/homepage
2) Download in hand, refer to worry-free
Oracle Database10gRelease 1 (10.1) Documentation
Http://www.oracle.com/technology/documentation/database10g.html
Oracle Database 10g Release 2 (10.2) Documentation
Http://www.oracle.com/technology/documentation/database10gR2.html
3.11g 1Oracle Official documentation
1) Online Browsing
Http://www.oracle.com/pls/db111/homepage
2) Download in hand, refer to worry-free
Oracle Database 11g Release 1 (11.1) Documentation
Http://www.oracle.com/technology/documentation/database11gR1.html
4.11GR2 Oracle Official Documentation
1) Online Browsing
Http://www.oracle.com/pls/db112/homepage
2) Download in hand, refer to worry-free
Oracle Database 11gRelease 2 (11.2) Documentation
http://www.oracle.com/technology/documentation/database.html (expired)
Oracle-official online document address