-gd DBA and -gm 1 usage clarification in SAP Sybase IQ
When I use ‘-gd DBA -gm 1’ to start up IQ1540 server,
One connection using non-DBA login ( ‘thomas’) to connect to IQ1540 OK !
The other connection using DBA login still can connect to IQ1540 without problem !!
This example confirmed what IQ1540 installation guide said – when ‘-gm 1’ set on start server configuration, an extra DBA login still can logon IQ server to issue command to kill other connection !!
- Picture 1 ( one non-DBA login + one DBA login )
Two ‘DBA’ logins are also worked !!
- Picture 2 ( one DBA login + one DBA login )
Two non-DBA logins hit the ‘-gm 1’ limit, and 2nd non-DBA connection cannot connect to IQ1540 server !!
- Picture 3 ( one non-DBA login + one non-DBA login )
From the Sybase IQ 1540 utility Guide, we can clearly know these two server option’s definition
-gm level => Limit the number of connections to the server that can be active at one time.
-gd level => Set the permission required to start and stop the database.
Please check following links for details on start_iq server options
-gd DBA and -gm 1 server options are used to limit user connection when DBA need to do some maintenance tasks;
for example: ‘alter database upgrade’ after installed software patches, change table schema, and rebuild indexes tasks.
-gm 1 can be used to limit non-DBA login only and only 1 non-DBA login can logon Sybase IQ server !!
However, it is not used to limit DBA login / login with DBA authority to logon Sybase IQ server !!
Actually, if one non-DBA login connected to Sybase IQ server, DBA can still open a new connection with DBA login / login with DBA authority
to logon Sybase IQ server and issue ‘drop connection conn-handle-number’ to clear that existing non-DBA login session to avoid other user interrupt DBA maintenance tasks !!
I hope this clarification is helpful to end users to clearly know the definition and usage of these 2 server options ( -gm and -gd ) !!