Oracle : Script to give a quick overveiw of the Instance

select /*+ RULE CURSOR_SHARING_EXACT */
   substrb(max(name),1,6) NAME,
   substrb(max(version),1,9) VERSION,
   substrb(to_char(max(startup_time),'DD-MON-YY'),1,9) STARTED,
   substrb(decode(max(log_mode),'NOARCHIVELOG','NOARCH','ARCH'),1,5) LOGMD,
   decode(max(archiver),'STOPPED','NO','YES') ARC,
   decode(max(logins),'ALLOWED','NO','YES') RM,
   substrb(max(parallel),1,3) OPS,
   to_char(max(E4031),'9999') "4031",
   substrb(decode(floor(max(pool_mb)/1073741824),0,
     decode(floor(max(pool_mb)/1048576),0,
       to_char(max(pool_mb)/1024,'9999')||'K',
       to_char(max(pool_mb)/1048576,'9999')||'M'),
     to_char(max(pool_mb)/1073741824,'99.9')||'G'),2,6) POOL,
   substrb(decode(floor(max(dbf_mb)/1073741824),0,
     decode(floor(max(dbf_mb)/1048576),0,
       to_char(max(dbf_mb)/1024,'9999')||'K',
       to_char(max(dbf_mb)/1048576,'9999')||'M'),
     to_char(max(dbf_mb)/1073741824,'99.9')||'G'),2,6) CACH,
   substrb(decode(floor(max(log_kb)/1073741824),0,
     decode(floor(max(log_kb)/1048576),0,
       to_char(max(log_kb)/1024,'9999')||'K',
       to_char(max(log_kb)/1048576,'9999')||'M'),
     to_char(max(log_kb)/1073741824,'99.9')||'G'),2,6) LOG,
   substrb(decode(floor(max(pga_sz)/1073741824),0,
     decode(floor(max(pga_sz)/1048576),0,
       to_char(max(pga_sz)/1024,'9999')||'K',
       to_char(max(pga_sz)/1048576,'9999')||'M'),
     to_char(max(pga_sz)/1073741824,'99.9')||'G'),2,6) PGA,
   substrb(decode(floor(max(jav_sz)/1073741824),0,
     decode(floor(max(jav_sz)/1048576),0,
       to_char(max(jav_sz)/1024,'9999')||'K',
       to_char(max(jav_sz)/1048576,'9999')||'M'),
     to_char(max(jav_sz)/1073741824,'99.9')||'G'),2,6) JAVA from (
   select
     vd.name name,
     vi.version version,
     vi.startup_time startup_time,
     vd.log_mode log_mode,
     vi.archiver archiver,
     vi.logins logins,
     vi.parallel parallel,
     xk.kghlunfu e4031,
     vp1.value POOL_MB,
     to_number(vp2.value*vp3.value) DBF_MB,
     vp4.value LOG_KB,
     vp5.value PGA_SZ,
     '0' JAV_SZ
   from v$database vd, v$instance vi, sys.x$kghlu xk, v$parameter vp1,
     v$parameter vp2, v$parameter vp3, v$parameter vp4, v$parameter vp5
   where vp1.name = 'shared_pool_size'
   and vp2.name = 'db_block_buffers'
   and vp2.value != '0'
   and vp3.name = 'db_block_size'
   and vp4.name = 'log_buffer'
   and vp5.name = 'sort_area_size'
   union all
   select
     vd.name,
     vi.version,
     vi.startup_time,
     vd.log_mode,
     vi.archiver archiver,
     vi.logins logins,
     vi.parallel parallel,
     xk.kghlunfu e4031,
     vp1.value POOL_MB,
     to_number(vp2.value) DBF_MB,
     vp4.value LOG_KB,
     vp5.value PGA_SZ,
     vp6.value JAV_SZ
   from v$database vd, v$instance vi, sys.x$kghlu xk, v$parameter vp1,
     v$parameter vp2, v$parameter vp4, v$parameter vp5, v$parameter vp6
   where vp1.name = 'shared_pool_size'
   and vp2.name = 'db_cache_size'
   and vp4.name = 'log_buffer'
   and vp5.name = 'pga_aggregate_target'
   and vp6.name = 'java_pool_size' )
 /