Dev: get client variable in pl/sql

SQL> var val varchar2(4000)
SQL> set autoprint on
SQL> exec sys.dbms_system.get_env('nls_lang',:val);

PL/SQL procedure successfully completed.


VAL
--------------------------------------------------------------------------------
AMERICAN_AMERICA.CL8MSWIN1251

shared pool free memory

--
-- Free memory in shared pool and in reserved_pool separately, percent of free space current and min for reserved pool
--
select s.pool, round((s.bytes - p.free_space)/1024/1024, 3) fm, round((p.free_space)/1024/1024, 3) fm_reserved
, round(((s.bytes - p.free_space)/decode(sps.value, 0, NULL, sps.value))*100, 3) pct_free
, round(((sps_reserved.value - p.max_used_size)/sps_reserved.value)*100, 3) pct_free_reserved_min
from v$sgastat s, v$shared_pool_reserved p, v$parameter sps, v$parameter sps_reserved
where s.pool = 'shared pool' and s.name = 'free memory'
and sps.name='shared_pool_size'
and sps_reserved.name='shared_pool_reserved_size'
;

peformance issue - nls_lang

set NLS_LANG=american_america.utf8
--
19:54:07 SQL> select * from character_set;

171080 rows selected.

Elapsed: 00:00:29.68

Statistics
----------------------------------------------------------
0 recursive calls
0 db block gets
3808 consistent gets
2009 physical reads
0 redo size
16942067 bytes sent via SQL*Net to client
1026 bytes received via SQL*Net from client
59 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
171080 rows processed
--
set NLS_LANG=
--
SQL> select * from character_set;

171080 rows selected.

Elapsed: 00:00:02.26

Statistics
----------------------------------------------------------
0 recursive calls
0 db block gets
14909 consistent gets
2855 physical reads
0 redo size
18383263 bytes sent via SQL*Net to client
125854 bytes received via SQL*Net from client
11407 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
171080 rows processed