oracle sga構成
SGA
1、Followed components can be managed auto.
1)shared pool(sql pl/sql execute, dictionary cache)
2)buffer cache(data buffer read from /write to disk;使用兩個list管理:write list/LRU list.)
The write list holds dirty buffers, which contain data that has been modified but has not yet been written to disk. The LRU list holds free buffers, pinned buffers, and dirty buffers that have not yet been moved to the write list.
3)redo buffer pool( redo buffer write to disk,log_buffer一般設定1M到3M,見注1)
4)large pool(rman backup buffer)
5)java pool(execute java)
6)stream pool()
2、Followed components can be managed mannually only.
■ Keep/Recycle buffer caches (controlled by DB_KEEP_CACHE_SIZE and DB_RECYCLE_CACHE_SIZE)
■ Additional buffer caches for non-standard block sizes (controlled by DB_nK_CACHE_SIZE, n = {2, 4, 8, 16, 32})
注1:
The initialization parameter LOG_BUFFER determines the size (in bytes) of the redo log
buffer. In general, larger values reduce log file I/O, particularly if transactions are long
or numerous. The default setting is either 512 kilobytes (KB) or 128 KB times the
setting of the CPU_COUNT parameter, whichever is greater.
重要引數說明:
sga_target 動態引數,可以透過alter system set sga_target=400M;
sga_max_size 靜態初始化引數。sga_target DB_BLOCK_SIZE=4096 (資料塊大小) USE_INDIRECT_DATA_BUFFERS(擴充套件記憶體引數) The USE_INDIRECT_DATA_BUFFERS parameter enables the use of the extended buffer cache mechanism for 32-bit platforms that can support more than 4 GB of physical memory. On platforms that do not support this much physical memory, this parameter is ignored. SGA相關檢視 select * from V$SGA_RESIZE_OPS; 也可以透過下面的sql查詢: SQL> select name,object_id,type from v$fixed_table where name like 'V%SGA%' ;
DB_CACHE_SIZE=1024M (預設資料塊大小4k對應的buffer cache)
DB_2K_CACHE_SIZE=256M(2k資料塊對應的buffer cache)
DB_8K_CACHE_SIZE=512M(8k資料塊對應的buffer cache)
select * from V$SGA_CURRENT_RESIZE_OPS;
select * from V$SGA_TARGET_ADVICE;
select * from V$SGA;
select * from V$SGAINFO;
select * from V$SGASTAT;
select * from V$SGA_DYNAMIC_COMPONENTS;
select * from V$SGA_DYNAMIC_FREE_MEMORY;
NAME OBJECT_ID TYPE
------------------------------ ---------- -----
V$SGA 4294950938 VIEW
V$SGASTAT 4294950939 VIEW
V$SGAINFO 4294952085 VIEW
V$SGA_CURRENT_RESIZE_OPS 4294951935 VIEW
V$SGA_RESIZE_OPS 4294951937 VIEW
V$SGA_DYNAMIC_COMPONENTS 4294951939 VIEW
V$SGA_DYNAMIC_FREE_MEMORY 4294951941 VIEW
V$SGA_TARGET_ADVICE 4294952616 VIEW
8 rows selected
SQL>
來自 “ ITPUB部落格 ” ,連結:http://blog.itpub.net/70612/viewspace-1023883/,如需轉載,請註明出處,否則將追究法律責任。
相關文章
- oracle體系結構梳理---SGA+PGAOracle
- Oracle記憶體結構研究-SGA篇Oracle記憶體
- Oracle 體系結構 SGA 和PGA 總結Oracle
- Oracle體系結構之記憶體結構(SGA、PGA)Oracle記憶體
- Sga的結構
- oracle PGA 構成Oracle
- oracle記憶體結構:SGA的區域資訊Oracle記憶體
- oracle sga相關Oracle
- Oracle記憶體結構(一)----SGA的區域資訊Oracle記憶體
- oracle10g SGAOracle
- oracle SGA配置和管理Oracle
- ORACLE SGA 的分配(轉)Oracle
- Oracle記憶體結構(一)----SGA的區域資訊(轉)Oracle記憶體
- ORACLE SGA之shared poolOracle
- oracle 92 修改sga過程Oracle
- Oracle SGA中的Granule(粒度)Oracle
- 變更oracle 11.2.0.3 rac sga自動管理為sga手工管理Oracle
- ORACLE RAC SGA引數調整Oracle
- oracle10g 修改 sga pgaOracle
- ORACLE SGA與共享內聯絡Oracle
- oracle 重設定sga_targetOracle
- ordebug 手動修改Oracle sga scnOracle
- Oracle10g修改SGA_TARGETOracle
- ORACLE 記憶體管理 之四 SGAOracle記憶體
- oracle10.2.0.2 bug "AUTO SGA: Not freeOracle
- 對ORACLE的SGA 進行檢查Oracle
- oracle 10g中的SGA_MAX_SIZE與SGA_TARGET引數Oracle 10g
- oracle10g_11g process程式及sga元件體系架構圖pictureOracle元件架構
- 變更oracle 11.2.0.3 rac sga手工管理為sga及pga全自動管理Oracle
- oracle 10g更改sga最大值Oracle 10g
- Oracle 10g SGA 相關的VIEWOracle 10gView
- 初識oracle SGA之引數設定Oracle
- AIX上pin住Oracle的SGA的方法AIOracle
- Oracle Rac 修改SGA_TARGET值無變化Oracle
- 一次Oracle診斷案例-SGA與SwapOracle
- Oracle 10g SGA 的自動化管理Oracle 10g
- oracle10g sga手工管理mmm之一Oracle
- AIX上pin住Oracle的SGA的方法(轉)AIOracle