DB Smart Flash Cache

The DB Smart Flash Cache is an extersion of the buffer cache that resides on a flash disk.  A flash disk is a solid state device made of flash memory like MP3 devices.  The flash devices is very fast because disk seek time is eliminated.  It has large capaciy and cheaper compared to DRAM.  Using the smart flash cache is mainly for read-intensive OLTP workloads.  The main benefits are:

• Better performance for the same price:  When the buffer cache memory is maxed out and I/O starts thrashing, you need to buy more memory and memory is not cheap and the system might has not enough DRAM slots.  You can use the flash cache future and configure with the main memory buffer cache to provide a much larget combine buffer cache that you can cache the whole working set of the database into flash cache to improve the response time and overall throughput.
• Easy to setup:  Two initialization parameters to be set

          DB_FLASH_CACHE_FILE:  specifies the OS file/disk path and the
          name for the flash cache.

          DB_FLASH_CACHE_SIZE:  is the name of the flash cache
          All Standard block size buffers use the same flash cache.  Nonstandard
          block size is not supported.  DB smart flash cache is not auto-tuned

• Fine-tune object-level granularity control of the LRU machanism