Versions Means

Oracle                      Microsoft      Sybase     IBM    Open Source

2.0                                    2.5            unix           DB2         MYSql
3.0                                    3.5           .                                  Postgre
4.0                                   4.5                                               Ingres
6.0                                    6.5                                              Informix
7.0 Application Base         7.0
8.0                                  2000
8i Web Base                   2005
9i                                     2008
10g Grid Computing
11i

Versions

  9.0.0.0.0  -------- Minor Patch
  9.0.0.1.0  -------- Major Patch
  9.0.2.1.0 --------- Minor Release
  9.4.2.1.0  ---------Major Release
10.0.0.0.0  -------   Version