ORACLE_修改執行個體的記憶體大小

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註：本文來源於：星火spark  《Oracle的執行個體佔用記憶體調整》

ORACLE_修改執行個體的記憶體大小一：修改oracle資料庫執行個體記憶體大小指令碼

  1  ---- 1、操作 （oracle使用記憶體約等於 SGA+PGA，所以可以減少SGA與PGA解決你的問題，生產庫慎用）  2 alter system set sga_max_size=100m scope=spfile; --減少SGA大小，靜態參數，重啟後生效  3 alter system set sga_target=80m scope=both; --動態參數；oracle推薦：啟動時修改此參數，不要動態設定此參數  4 alter system set pga_aggregate_target=40m sope=both; ---減少pga大小

二：知識點拓展：

SGA_MAX_SIZE的大小不是隨意指定的，必須滿足一定條件的。
sga_max_size=100M,必須滿足SGA所有組件的最小和；至少滿足db_cache_size,log_buffer,shared_pool_size,large_pool_size,java_pool_size總和的大小)

  1 oracle記憶體結構介紹：  2 Introduction to Oracle Memory Structures  3 Oracle uses memory to store information such as the following:  4   5 Program code  6 Information about a connected session, even if it is not currently active  7 Information needed during program execution (for example, the current state of a query from which rows are being fetched)  8 Information that is shared and communicated among Oracle processes (for example, locking information)  9 Cached data that is also permanently stored on peripheral memory (for example, data blocks and redo log entries) 10 The basic memory structures associated with Oracle include: 11 System Global Area (SGA), which is shared by all server and background processes. 12 Program Global Areas (PGA), which is private to each server and background process; there is one PGA for each process. 13  14 1.sqlplus “/ as sysdba"  2. 3.create pfile=‘d:/cj.ora‘ from spfile;  然後去你的oracle安裝目錄 15 　　找一個init資料庫名。ora這樣一個檔案 16  17 　　把幾個oracle記憶體參數改小點 18  19 　　一個2G的記憶體是如下配置的： 20  21 　　*.sga_max_size=712M 22  23 　　*.large_pool_size=8M 24  25 　　*.shared_pool_size=250M 26  27 　　*.sort_area_size=0.5M 28  29 　　*.db_cache_size=350M 30  31 　　然後shutdown資料庫 32  33 　　1.shutdown immediate;  2. 3.create spfile from pfile=‘d:/cj2.ora‘;  4. 5.startup;  然後啟動，就可以了。 34  35 　　以上就是調整oracle記憶體參數，減少資料庫記憶體佔用的方法介紹。

ORACLE_修改執行個體的記憶體大小