How to check db2 version

Both worked for me.

SELECT * FROM TABLE(SYSPROC.ENV_GET_INST_INFO());

or

SELECT * FROM SYSIBMADM.ENV_INST_INFO;

Another one in v11:

select CURRENT APPLICATION COMPATIBILITY from sysibm.sysdummy1

Result:

V11R1

It's not the current version, but the current configured level for the application.

In z/OS while on version 10, use of CURRENT APPLICATION COMPATIBILITY is not allowed. You will have to resort to:

SELECT GETVARIABLE('SYSIBM.VERSION') AS VERSION,
       GETVARIABLE('SYSIBM.NEWFUN')  AS COMPATIBILITY
FROM SYSIBM.SYSDUMMY1;

Here is a link to all the variables available: https://www.ibm.com/support/knowledgecenter/SSEPEK_12.0.0/sqlref/src/tpc/db2z_refs2builtinsessionvars.html#db2z_refs2builtinsessionvars

db2ls command will display the db2level along with the install path and install date.

To determine the specific product installed:

db2ls -p -q -b <installpath>

on db2ls command.

The following will appear:

Install Path       Level   Fix Pack   Special Install Number   Install Date    Installer UID
--------------------------------------------------------------------------------------------
/opt/ibm/db2/V9.7  9.7.0.7        7                      Thu Aug  1 12:25:53 2013 CDT     0

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