title: Get DB2 instance name using SQL
body: <p>Is it possible to find the instance name of a DB2 database by querying the catalog metadata? For instance, we can find the columns of tables using <code>SELECT tbname, column_name FROM SYSIBM.SYSCOLUMNS</code>. Is there an analogous query that can get the instance name?</p>
  
  <p>I need this because I am running a query to get the remaining free space in the DB, across several instances. I would prefer to have the query itself tell me the name of the instance.</p>
  
  <p>Running DB2 10.5 on Linux.</p>