What is flash cache in Exadata?
The Exadata Smart Flash Cache is a cache for storing redo data until this data is safely written to disk. The Exadata Storage Server comes with a substantial amount of flash storage. A small amount is allocated for database logging and the remainder will be used for caching user data.
How much flash memory comes with each Exadata storage cell?
Exadata Smart Flash Cache Each Exadata Storage Server includes 4 PCI flash cards with a total raw capacity of 3.2 TB of flash memory.
How do I monitor Exadata?
Monitoring Tools There are two approaches for monitoring Oracle Exadata Storage Servers: using a command-line interface (CLI) or using the graphical interface provided by the Oracle Enterprise Manager Cloud Control 12c console. Command-line interface.
What are the three main Exadata services?
The major components of an Exadata Cloud Service include:
- Database Servers.
- Storage Servers.
- InfiniBand.
- Networks.
- Oracle Management Console.
What is Exadata storage Index?
Storage Indexes are a feature unique to Oracle Exadata. A storage index is a memory-based structure that reduces the amount of physical IO required by the cell. A storage index keeps track of minimum and maximum values from query predicates and builds storage index regions based on usage.
What is smart scan in Exadata?
The Smart Scan feature in Exadata enables SQL processing to happen at the storage tier, instead of the database tier, to improve query performance. Smart Scan reduces the volume of data sent to the database tier thereby reducing the CPU usage on database nodes.
What is cell node in Exadata?
Also known as Database Node or Compute Node. This is where the database, ASM and clusterware are run. The clients connect to this. Runs Oracle Enterprise Linux. Cell.
How do you check Exadata half rack or full rack?
Login to the exadata compute node 1 and navigate to the following directory. and you will get the below output detailing about the exadata model you are just playing with. In above output you would see that our current Exadata Database Machine Model is X3-2 Half Rack High Capacity with 3TB size of each HDD.
What is cell in Exadata?
Cell Servers, which we call also Storage Server, play the most critical role for Exadata. Because This is the main Server for Exadata that perform the magic features such as Hybrid Columnar Compression (HCC), Storage Index, Smart Scan (Query Offloading) and Smart Flash Cache & IORM.
How do you discover Exadata machine in OEM 13c?
Enter the SYSMAN user and password or any other user with admin privileges. Select “Oracle Exadata Database Machine” and click Add button. On this page, search or enter the EM agent URL for compute node 1 and, Click Add buton and add the compute node 1 and enter the oracle user credentials. Note: Make databasemachine.
What is Oracle Exadata architecture?
Exadata Database Machine is a modern architecture featuring scale-out industry-standard database servers, scale-out intelligent storage servers, and an extremely high speed internal RDMA Network Fabric that connects the database and storage servers.
What is Exadata DB system?
Exadata is a database machine designed by Oracle that provides users with optimized functionality pertaining to enterprise class databases and their associated workloads. Exadata is a composite database server machine that uses Oracle database software and the hardware server equipment developed by Sun Microsystems.
What statistics are populated when Exadata Smart Flash Cache is in write-back?
These statistics are populated when Exadata Smart Flash Cache is in Write-Back mode. The Disk Writer IO Detail columns relate to internal I/Os performed to persist data from Exadata Smart Flash Cache to hard disk devices. These columns show both the reads from flash and the writes to hard disk. Flash Cache Internal Writes
What is FC_by_allocated in Exadata Flash Cache?
Space in Exadata Smart Flash Cache is internally managed in chunks known as cachelines. FC_BY_ALLOCATED represents the amount of space (in megabytes) that is allocated to cachelines in the flash cache. If the value is close to the flash cache size, then the flash cache is fully populated.
What is RAM cache in Exadata?
A random access memory (RAM) cache feature was added in Oracle Exadata System Software release 18.1, prior to the introduction of PMEM cache. The RAM cache boosts OLTP read performance at the cost of using additional storage server memory.
Is the Exadata Smart Flash Logging feature ineffective?
This does not mean that the Exadata Smart Flash Logging feature is ineffective or unnecessary. Grid disk metrics provide information about the I/O load for grid disks, such as the number of large blocks read from a grid disk.