dbms/type is a SAP Parameter attribute which is used to control information. This is available within R/3 SAP systems depending on the version and release level.
Below is the standard documentation available and a few details of the attributes values .
The parameter is evaluated when the application server is started. Valid
values are:
ada: SAP MaxDB
db2: DB2 with OS390
db4: DB2 with AS400
db6: DB2 with UNIX/Microsoft Windows NT
hdb: SAP HANA
mss: Microsoft SQL Server
ora: Oracle
syb: Sybase
See SAP Parameter Documentation for full SAP documentation for this profile parameter.