Determine if the SGA_TARGET is already at the SGA_SIZE with the lowest ESTD_DB_TIME and/or ESTD_PHYSICAL_READS. SQL> startup ORACLE instance started. Total System Global Area 1,2828E+10 bytes If you are using a newer 64 bit OS, then you would have no practical limit to the size of the SGA. Total System Global Area 6.8413E+10 bytes Fixed Size 2270360 bytes Variable Size 3087010664 bytes Database Buffers 6.5230E+10 bytes Redo Buffers 93585408 bytes Database mounted. If not, then to get the best performance from the SGA, the SGA_TARGET should be changed to the optimal SGA_SIZE. Applies to: Oracle Database - Standard Edition - Version 10.1.0.2 to 11.2.0.2.0 [Release 10.1 to 11.2] Oracle Database Cloud Schema Service - Version N/A and later Database dismounted. It would only depend on the amount of physical memory. This means that I can max increase SGA_TARGET to 5 GB and not beyond that. ORACLE instance shut down. SGA_MAX_SIZE define the total max value SGA_TARGET can take. In Oracle Database 10g, Automatic Shared Memory Management (ASMM) feature is introduced to automatically determine the size of Database buffer cache (default pool), Shared Pool, Large pool and Java pool (starting with 10gR2, the streams pool is included) by setting the parameter SGA_TARGET. This feature reduces the tasks like dynamically analyzing the database workload and redistribute memory … SQL> alter system set sga_target=0; System altered. oraenv sqlplus as / sysdba SQL> show parameter sga_max_size NAME TYPE VALUE----- ----- -----sga_max_size big integer 9G. SQL> shut immediate Database closed. SGA_MAX_SIZE is not dynamic parameter but SGA_TARGET is. … SQL> show parameter sga_ NAME TYPE VALUE----- ----- -----sga_max_size big integer 64G sga_target big integer 64G If there's SGA_MAX_SIZE set in pfile, you should raise SGA_MAX_SIZE first, then raise … So you should provide the following: 32 bit/64 bit, operating system and version, hardware type including chip set. The same way SGA_TARGET defines the total size of SGA. sga_max_size and sga_target In this post, I am going to be demonstrating the basics of working of the sga_max_size and sga_target and also to cover some myths of playing around with these parameters. Database opened. sga_max_size big integer 956M SQL> alter system set sga_target=900m; System altered. For example, server RAM is 10 GB, SGA_MAX_SIZE is 5 GB and SGA_TARGET is 3 GB. SQL> alter system set sga_max_size=9g sid='*' scope=spfile; SQL> exit; shutdown database PROD (three instances should be shut down) $ srvctl stop database -d RAC $ srvctl START database -d RAC Verify Current Memory Parameters after the change: export ORACLE_SID=RAC1.
Disable SGA_TARGET We can Disable our automatic SGA tuning by setting the parameter SGA_TARGET to value digit 0.
Sga target not modified after setting sga_target to new value in RAC (Doc ID 1426733.1) Last updated on JULY 26, 2019. pre_page_sga boolean FALSE sga_max_size big integer 12G sga_target big integer 0 SQL> alter system set sga_max_size=0 scope=spfile; System altered.