11g

10年積累的成都做網(wǎng)站、成都網(wǎng)站制作經(jīng)驗，可以快速應對客戶對網(wǎng)站的新想法和需求。提供各種問題對應的解決方案。讓選擇我們的客戶得到更好、更有力的網(wǎng)絡服務。我雖然不認識你，你也不認識我。但先建設網(wǎng)站后付款的網(wǎng)站建設流程，更有高青免費網(wǎng)站建設讓你可以放心的選擇與我們合作。

[root@roidb1 ~]# su - oracle
<roidb1:orcl1:/home/oracle>$sqlplus / as sysdba

SQL*Plus: Release 11.2.0.4.0 Production on Wed Dec 13 21:40:51 2017

Copyright (c) 1982, 2013, Oracle.  All rights reserved.

Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
With the Partitioning, Real Application Clusters, Automatic Storage Management, OLAP,
Data Mining and Real Application Testing options

SQL> show parameter pga;

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
pga_aggregate_target                 big integer 0
SQL>

12c

[root@rac01 ~]# su - oracle
Last login: Fri Dec  8 16:09:27 CST 2017 on pts/0
<rac01:orcl1:/home/oracle>$sqlplus / as sysdba

SQL*Plus: Release 12.1.0.2.0 Production on Wed Dec 13 21:33:48 2017

Copyright (c) 1982, 2014, Oracle.  All rights reserved.

Connected to:
Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit Production
With the Partitioning, Real Application Clusters, Automatic Storage Management, OLAP,
Advanced Analytics and Real Application Testing options

SYS@orcl1> show parameter pga;

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
pga_aggregate_limit                  big integer 2G
pga_aggregate_target                 big integer 390M
SYS@orcl1>

--官方解釋
Property    Description
Parameter type

Big integer

Syntax

PGA_AGGREGATE_LIMIT = integer [K | M | G]

Default value

By default, PGA_AGGREGATE_LIMIT is set to the greater of 2 GB, 200% of PGA_AGGREGATE_TARGET, and 3 MB times the PROCESSES parameter. It will be set below 200% of PGA_AGGREGATE_TARGET if it is larger than 90% of the physical memory size minus the total SGA size, but not below 100% of PGA_AGGREGATE_TARGET.

Modifiable

ALTER SYSTEM

Modifiable in a PDB

No

Range of values

Oracle recommends that you do not set PGA_AGGREGATE_LIMIT below its default value. PGA_AGGREGATE_LIMIT cannot be set below its default value except in a text initialization parameter file (pfile) or binary server parameter file (spfile). If a value of 0 is specified, it means there is no limit to the aggregate PGA memory consumed by the instance.

Basic

No

PGA_AGGREGATE_LIMIT specifies a limit on the aggregate PGA memory consumed by the instance.

There is no difference in behavior between PGA_AGGREGATE_LIMIT being explicitly set or being set to the default.

SYS@orcl1> show parameter pga;

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
pga_aggregate_limit                  big integer 2G
pga_aggregate_target                 big integer 390M
SYS@orcl1> alter system set pga_aggregate_limit=3G  --動態(tài)修改

System altered.

SYS@orcl1> show parameter pga;

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
pga_aggregate_limit                  big integer 3G
pga_aggregate_target                 big integer 390M
SYS@orcl1> alter system set pga_aggregate_limit=350m;
alter system set pga_aggregate_limit=350m
*
ERROR at line 1:
ORA-02097: parameter cannot be modified because specified value is invalid
ORA-00093: pga_aggregate_limit must be between 2048M and 100000G
--大小不能小于2G
SYS@orcl1> alter system set pga_aggregate_limit=2048m;

System altered.

SYS@orcl1> alter system set pga_aggregate_limit=2047m;
alter system set pga_aggregate_limit=2047m
*
ERROR at line 1:
ORA-02097: parameter cannot be modified because specified value is invalid
ORA-00093: pga_aggregate_limit must be between 2048M and 100000G

SYS@orcl1>

在 Oracle 12c R1 之前，沒有選項可以用來限制和控制 PGA 的大小。雖然你設置某個大小為 PGA_AGGREGATE_TARGET 的初始參數(shù)，Oracle 會根據(jù)工作負載和需求來動態(tài)地增大或減小 PGA 的大小。而在 12c 中，你可以通過開啟自動 PGA 管理來對 PGA 設定硬性限制，這需要對 PGA_AGGREGATE_LIMIT 參數(shù)進行設置。因此，你現(xiàn)在可以通過設置新的參數(shù)來對 PGA 設定硬性限制以避免過度使用 PGA。

另外有需要云服務器可以了解下創(chuàng)新互聯(lián)scvps.cn，海內外云服務器15元起步，三天無理由+7*72小時售后在線，公司持有idc許可證，提供“云服務器、裸金屬服務器、高防服務器、香港服務器、美國服務器、虛擬主機、免備案服務器”等云主機租用服務以及企業(yè)上云的綜合解決方案，具有“安全穩(wěn)定、簡單易用、服務可用性高、性價比高”等特點與優(yōu)勢，專為企業(yè)上云打造定制，能夠滿足用戶豐富、多元化的應用場景需求。

本文題目：12c新特性之PGA_AGGREGATE_LIMIT-創(chuàng)新互聯(lián)
網(wǎng)頁路徑：http://chinadenli.net/article16/dgcgdg.html

成都網(wǎng)站建設公司_創(chuàng)新互聯(lián)，為您提供靜態(tài)網(wǎng)站、自適應網(wǎng)站、ChatGPT、網(wǎng)站建設、關鍵詞優(yōu)化、做網(wǎng)站

廣告

聲明：本網(wǎng)站發(fā)布的內容（圖片、視頻和文字）以用戶投稿、用戶轉載內容為主，如果涉及侵權請盡快告知，我們將會在第一時間刪除。文章觀點不代表本網(wǎng)站立場，如需處理請聯(lián)系客服。電話：028-86922220；郵箱：631063699@qq.com。內容未經(jīng)允許不得轉載，或轉載時需注明來源： 創(chuàng)新互聯(lián)