select instance_name from v$instance;
SELECT STATUS FROM V$INSTANCE;
select inst_id,count(inst_id) from gv$session group by inst_id;
------------tablespacle space-----------------------------
col tablespace_name for a15;
select d.tablespace_name,space "sum_space(m)",blocks sum_blocks,space-nvl(free_space,0) "used_space(m)",round((1-nvl(free_space,0)/space)*100,2) "used_rate(%)",free_space "free_space(m)" from (select tablespace_name,round(sum(bytes)/(1024*1024),2) space,sum(blocks) blocks from dba_data_files group by tablespace_name) d,(select tablespace_name,round(sum(bytes)/(1024*1024),2) free_space from dba_free_space group by tablespace_name) f where d.tablespace_name = f.tablespace_name(+) union all
select d.tablespace_name,space "sum_space(m)",blocks sum_blocks,used_space "used_space(m)",round(nvl(used_space,0)/space*100,2) "used_rate(%)",nvl(free_space,0) "free_space(m)" from (select tablespace_name,round(sum(bytes)/(1024*1024),2) space,sum(blocks) blocks from dba_temp_files group by tablespace_name) d,(select tablespace_name,round(sum(bytes_used)/(1024*1024),2) used_space,round(sum(bytes_free)/(1024*1024),2) free_space from v$temp_space_header group by tablespace_name) f where d.tablespace_name = f.tablespace_name(+);
