[Oracle] Java Pool

이론1. 자바풀 메모리 영역이 필요한 이유

💡 오라클에서 자바 코드를 컴파일 할 수 있는데
--> 이때 사용하는 메모리 영역이 자바 풀입니다.

이론2. 오라클의 메모리 영역 중 자동 조절되지 않는 영역은?

💡 리두 로그 버퍼

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실습1. 오라클 메모리 영역에서 현재 사용된 사이즈를 확인하시오

PROMPT *** CURRENT parameter settings ***
col name format a12
col VALUE format a8
SHOW parameter sga_
PROMPT
PROMPT *** SGA Dynamic Component SIZE Information***
col component format a22
col current_size format a15
col min_size format a15

SELECT component,current_size/1048576||'M' current_size,
       min_size/1048576||'M' min_size
FROM v$sga_dynamic_components
WHERE component IN ('shared pool','large pool',
                   'java pool','DEFAULT buffer cache');

col name format a20
col VALUE format a20
PROMPT *** CURRENT parameter settings IN V$PARAMETER *** 

SELECT name, VALUE, isdefault 
FROM v$parameter
WHERE name IN ('shared_pool_size','large_pool_size',
               'java_pool_size', 'db_cache_size'); 

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실습2. 자바코드를 오라클에서 수행하시오

set echo on

DECLARE
i NUMBER;
v_sql VARCHAR2(200);
BEGIN
  FOR i IN 1..200 LOOP
    -- Build up a dynamic statement to create a uniquely named java stored proc.
    -- The "chr(10)" is there to put a CR/LF in the source code.
    v_sql := 'create or replace and compile' || chr(10) ||
             'java source named "SmallJavaProc' || i || '"'  || chr(10) ||
             'as' || chr(10) ||
             'import java.lang.*;' || chr(10) ||
             'public class Util' || i || ' extends Object' || chr(10) ||
             '{ int v1=1;int v2=2;int v3=3;int v4=4;int v5=5;int v6=6;int v7=7; }';
    EXECUTE IMMEDIATE v_sql;
  END LOOP;
END;
/

SQL> @sga
*** CURRENT parameter settings ***

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
sga_max_size                         big integer 1888M
sga_min_size                         big integer 0
sga_target                           big integer 1888M
unified_audit_sga_queue_size         integer     1048576

*** SGA Dynamic Component SIZE Information***

COMPONENT              CURRENT_SIZE    MIN_SIZE
---------------------- --------------- ---------------
shared pool            416M            416M
large pool             16M             16M
java pool              0M              0M
DEFAULT buffer cache   1328M           1328M

*** CURRENT parameter settings IN V$PARAMETER ***

NAME                 VALUE                ISDEFAULT
-------------------- -------------------- ---------
shared_pool_size     0                    TRUE
large_pool_size      16777216             FALSE
java_pool_size       0                    TRUE
db_cache_size        0                    TRUE

SQL> ed java.sql

SQL> @java
SQL>
SQL> DECLARE
  2  i NUMBER;
  3  v_sql VARCHAR2(200);
  4  BEGIN
  5    FOR i IN 1..200 LOOP
  6      -- Build up a dynamic statement to create a uniquely named java stored proc.
  7      -- The "chr(10)" is there to put a CR/LF in the source code.
  8      v_sql := 'create or replace and compile' || chr(10) ||
  9               'java source named "SmallJavaProc' || i || '"'  || chr(10) ||
 10               'as' || chr(10) ||
 11               'import java.lang.*;' || chr(10) ||
 12               'public class Util' || i || ' extends Object' || chr(10) ||
 13               '{ int v1=1;int v2=2;int v3=3;int v4=4;int v5=5;int v6=6;int v7=7; }';
 14      EXECUTE IMMEDIATE v_sql;
 15    END LOOP;
 16  END;
 17  /

PL/SQL 처리가 정상적으로 완료되었습니다.

SQL>
SQL> @sga
SQL>
SQL> PROMPT *** CURRENT parameter settings ***
*** CURRENT parameter settings ***
SQL> col name format a12
SQL> col VALUE format a8
SQL> SHOW parameter sga_

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
sga_max_size                         big integer 1888M
sga_min_size                         big integer 0
sga_target                           big integer 1888M
unified_audit_sga_queue_size         integer     1048576
SQL> PROMPT

SQL> PROMPT *** SGA Dynamic Component SIZE Information***
*** SGA Dynamic Component SIZE Information***
SQL> col component format a22
SQL> col current_size format a15
SQL> col min_size format a15
SQL>
SQL> SELECT component,current_size/1048576||'M' current_size,
  2         min_size/1048576||'M' min_size
  3  FROM v$sga_dynamic_components
  4  WHERE component IN ('shared pool','large pool',
  5                     'java pool','DEFAULT buffer cache');

COMPONENT              CURRENT_SIZE    MIN_SIZE
---------------------- --------------- ---------------
shared pool            416M            416M
large pool             16M             16M
java pool              64M             0M
DEFAULT buffer cache   1264M           1264M

SQL>
SQL> col name format a20
SQL> col VALUE format a20
SQL> PROMPT *** CURRENT parameter settings IN V$PARAMETER ***
*** CURRENT parameter settings IN V$PARAMETER ***
SQL>
SQL> SELECT name, VALUE, isdefault
  2  FROM v$parameter
  3  WHERE name IN ('shared_pool_size','large_pool_size',
  4                 'java_pool_size', 'db_cache_size');

NAME                 VALUE                ISDEFAULT
-------------------- -------------------- ---------
shared_pool_size     0                    TRUE
large_pool_size      16777216             FALSE
java_pool_size       0                    TRUE
db_cache_size        0                    TRUE