Rafael, no caso da quantidade de memória envolvida o AMM não me parece o mais indicado.
Citando: When you have large SGA sizes you can get considerable benefits from using <http://www.oracle-base.com/articles/linux/configuring-huge-pages-for-oracle-on-linux-64.php> HugePages. Automatic Memory Management and HugePages on Linux are not compatible, which means AMM is probably not a sensible option for any large systems. Instead, <http://www.oracle-base.com/articles/10g/performance-tuning-enhancements-10g.php#automatic_shared_memory_management> Automatic Shared Memory Management and <http://www.oracle-base.com/articles/9i/memory-management-9i.php#AutomaticSQLExecutionMemoryManagement> Automatic PGA Management should be used as they are compatible with HugePages. http://www.oracle-base.com/articles/11g/automatic-memory-management-11gr1.php Samuel, é muito mais complexo que esses parâmetros apenas que tu passou, por exemplo, tem hugepages configurado nesse servidor? Os parâmetros de banco lock_sga e pre_page_sga como estão? Ainda, recomendo algumas notas: <https://support.oracle.com/epmos/faces/ui/km/SearchDocDisplay.jspx?id=401749.1&type=DOCUMENT&displayIndex=3> Shell Script to Calculate Values Recommended Linux HugePages / HugeTLB Configuration[Article ID 401749.1] <https://support.oracle.com/epmos/faces/ui/km/SearchDocDisplay.jspx?id=361323.1&type=DOCUMENT&displayIndex=5> HugePages on Linux: What It Is... and What It Is Not...[Article ID 361323.1] Nessa nota acima cito o seguinte tópico: Advantages of HugePages Over Normal Sharing Or AMM (see below) * Not swappable: HugePages are not swappable. Therefore there is no page-in/page-out mechanism overhead.HugePages are universally regarded as pinned. * Relief of TLB pressure: * Hugepge uses fewer pages to cover the physical address space, so the size of “book keeping” (mapping from the virtual to the physical address) decreases, so it requiring fewer entries in the TLB * TLB entries will cover a larger part of the address space when use HugePages, there will be fewer TLB misses before the entire or most of the SGA is mapped in the SGA * Fewer TLB entries for the SGA also means more for other parts of the address space * Decreased page table overhead: Each page table entry can be as large as 64 bytes and if we are trying to handle 50GB of RAM, the pagetable will be approximately 800MB in size which is practically will not fit in 880MB size lowmem (in 2.4 kernels - the page table is not necessarily in lowmem in 2.6 kernels) considering the other uses of lowmem. When 95% of memory is accessed via 256MB hugepages, this can work with a page table of approximately 40MB in total. See also Document 361468.1 <https://support.oracle.com/epmos/faces/ui/km/DocumentDisplay.jspx?id=361468.1> . * Eliminated page table lookup overhead: Since the pages are not subject to replacement, page table lookups are not required. * Faster overall memory performance: On virtual memory systems each memory operation is actually two abstract memory operations. Since there are fewer pages to work on, the possible bottleneck on page table access is clearly avoided. De: oracle_br@yahoogrupos.com.br [mailto:oracle_br@yahoogrupos.com.br] Em nome de Rafael Mendonca Enviada em: terça-feira, 5 de fevereiro de 2013 17:07 Para: oracle_br@yahoogrupos.com.br Assunto: Re: [oracle_br] URGENTE - SGA x PGA Porque vc não ativa o memory_target e deixa com que o Oracle se preocupe com isso ? Já li alguns livros que a partir da versão 11G R2 o Oracle administra as 2 memórias(SGA e PGA) muito melhor do que muito DBA expert por aí. ________________________________ De: Samuel Santos samuel.gsan...@yahoo.com.br <mailto:samuel.gsantos%40yahoo.com.br> > Para: oracle_br oracle_br@yahoogrupos.com.br <mailto:oracle_br%40yahoogrupos.com.br> > Enviadas: Terça-feira, 5 de Fevereiro de 2013 17:03 Assunto: [oracle_br] URGENTE - SGA x PGA Pessoal, Boa Tarde! Peço-lhes uma ajuda para solucionar um problema crítico de carga de dados no servidor de um cliente, segue as características do ambiente: Modelo: DELL R710 - 2Us S/T: B3Q82R1 2 Processadores Six-Core 2,40 GHZ Memória 144G 2 HDs de 1T Servidor não possui placa HBA Sistema Operacional: Red Hat 5.8 Enterprise 64B Oracle Enterprise 11.2.0.3 O que vc's sugerem para alteração\ajuste nos paramentros de SGA, PGA, etc? SQL> show parameter target NAME TYPE VALUE ------------------------------------ ----------- ------------------------------ archive_lag_target integer 0 db_flashback_retention_target integer 1440 fast_start_io_target integer 0 fast_start_mttr_target integer 0 memory_max_target big integer 0 memory_target big integer 0 parallel_servers_target integer 192 pga_aggregate_target big integer 29842M sga_target big integer 89600M [As partes desta mensagem que não continham texto foram removidas] [As partes desta mensagem que não continham texto foram removidas] [As partes desta mensagem que não continham texto foram removidas]
