cluvfy Healthcheck

Normally we run cluvfy in preparation of the installation of Grid Infrastructure or a set of RAC binaries to ensure everything is ready for the next step in the RAC install process. Beginning with 11.2.0.3, there is another option  "healthcheck" 

Part of the “comp” checks, it takes the following options:

Datapump import gets ORA-600 [kpudpxcs_ctxConvertStream_ref_1] while importing Spatial data

Working for one of our client , just got the below error in impdp log for some tables, one example below.

ORA-31693: Table data object "GDB"."STREETS" failed to load/unload and is being
skipped due to error:
ORA-02354: error in exporting/importing data
ORA-00600: internal error code, arguments: [kpudpxcs_ctxConvertStream_ref_1],
 [SYS_TYPEID("SHAPE")], [], [], [], [], [], [], [], [], [], []

Send Message to Users by OS Command using PL/SQL

From one of my client ,it was required to send the message to application users (on Windows) for specific events by the database server. I used  the simple msg (Win command) for this purpose , example given below :

How To Connect database in sqlplus without tnsnames.ora

Many times we have requirement of connecting database to execute a sql script but we sometimes don't find the tnsnames.ora file and sometimes we don't have permission to edit (one of my client faced issue on Windows 2008 Server).