12c新特性之PGA_AGGREGATE_LIMIT-創(chuàng)新互聯(lián)

11g

10年積累的成都做網(wǎng)站、成都網(wǎng)站制作經(jīng)驗(yàn)，可以快速應(yīng)對(duì)客戶對(duì)網(wǎng)站的新想法和需求。提供各種問(wèn)題對(duì)應(yīng)的解決方案。讓選擇我們的客戶得到更好、更有力的網(wǎng)絡(luò)服務(wù)。我雖然不認(rèn)識(shí)你，你也不認(rèn)識(shí)我。但先建設(shè)網(wǎng)站后付款的網(wǎng)站建設(shè)流程，更有高青免費(fèi)網(wǎng)站建設(shè)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(dòng)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(méi)有選項(xiàng)可以用來(lái)限制和控制 PGA 的大小。雖然你設(shè)置某個(gè)大小為 PGA_AGGREGATE_TARGET 的初始參數(shù)，Oracle 會(huì)根據(jù)工作負(fù)載和需求來(lái)動(dòng)態(tài)地增大或減小 PGA 的大小。而在 12c 中，你可以通過(guò)開(kāi)啟自動(dòng) PGA 管理來(lái)對(duì) PGA 設(shè)定硬性限制，這需要對(duì) PGA_AGGREGATE_LIMIT 參數(shù)進(jìn)行設(shè)置。因此，你現(xiàn)在可以通過(guò)設(shè)置新的參數(shù)來(lái)對(duì) PGA 設(shè)定硬性限制以避免過(guò)度使用 PGA。

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

本文題目：12c新特性之PGA_AGGREGATE_LIMIT-創(chuàng)新互聯(lián)
網(wǎng)頁(yè)路徑：http://muchs.cn/article16/dgcgdg.html

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

廣告

聲明：本網(wǎng)站發(fā)布的內(nèi)容（圖片、視頻和文字）以用戶投稿、用戶轉(zhuǎn)載內(nèi)容為主，如果涉及侵權(quán)請(qǐng)盡快告知，我們將會(huì)在第一時(shí)間刪除。文章觀點(diǎn)不代表本網(wǎng)站立場(chǎng)，如需處理請(qǐng)聯(lián)系客服。電話：028-86922220；郵箱：631063699@qq.com。內(nèi)容未經(jīng)允許不得轉(zhuǎn)載，或轉(zhuǎn)載時(shí)需注明來(lái)源： 創(chuàng)新互聯(lián)

成都網(wǎng)頁(yè)設(shè)計(jì)公司