Smart Flash Cache in Oracle Exadata -1

Hi,

I will explain Smart Flash cache feature of Oracle Exadata in this article.

 

Before this post, If you don’t know What is the Exadata and want to learn, you can read following Exadata Tutorials.

 

 

One of Exadata’s unique and perfect features is the Smart Flash Cache. Exadata moves frequently accessed data ( Table, Headers of Table, Index, Controlfile and Datafile ) to Flash cache and process these data in the Flash cache to avoid I/O latencies.

Smart Flash Cache feature is performed automatically in the Storage Server without the user  having to take any action.

 

The Smart Flash Cache feature is a very smart mechanism, so it decides which data is kept in Flash cache without the intervention of users. But Exadata provides users CELL_FLASH_CACHE feature to cache some of the objects’ segments and give priority to the caching of these objects. In general, the Smart Flash Cache feature is very smart feature in that it does not cache data that is rarely or never used.

 

 

 

Architecture of Smart Flash cache is like following.

There are 56 PCI flash cards in a full X4-2 machine as follows and 44.8 TB raw physical flash memory. These sizes and counts may change in the Exadata X5, X6, X7 and X8.

 

 

There are 4 PCI flash memories with 3.2 TB in each Storage Server. The Smart Flash Cache settings are done the first installation and can be changed after first installation.

 

 

 

You can connect to each Storage Server and execute the following queries with the CellCLI tool and query the Flash Cache’s name, size, status and mode.

 

 

 

Mehmet Salih Deveci

I am Founder of IT Tutorial and Certified Expert about Oracle & SQL Server database, Goldengate, Exadata Machine, Oracle Database Appliance administrator with 10+years experience.I have OCA, OCP, OCE RAC Expert Certificates I have worked 100+ Banking, Insurance, Finance, Telco and etc. clients as a Consultant, Insource or Outsource.I have done 200+ Operations in this clients such as Exadata Installation & PoC & Migration & Upgrade, Oracle & SQL Server Database Upgrade, Oracle RAC Installation, SQL Server AlwaysOn Installation, Database Migration, Disaster Recovery, Backup Restore, Performance Tuning, Periodic Healthchecks.I have done 2000+ Table replication with Goldengate or SQL Server Replication tool for DWH Databases in many clients.If you need Oracle DBA, SQL Server DBA, APPS DBA,  Exadata, Goldengate, EBS Consultancy and Training you can send my email adress mehmetsalih.deveci@outlook.com.-                                                                                                                                                                                                                                                 -Oracle DBA, SQL Server DBA, APPS DBA,  Exadata, Goldengate, EBS ve linux Danışmanlık ve Eğitim için  mehmetsalih.deveci@outlook.com a mail atabilirsiniz.

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