Flash Usage Models for the Oracle Database

• Transparent disk replacement for databases– One for one replacement for conventional disks– Array caching layer– Auto-tiering storage layerFlash storage is transparent to the database and managed by the

storage layer. The management of flash storage does not possess knowledge for how the database functions.

• Fast storage managed by the database kernel– Database Smart Flash Cache– Exadata Smart Flash CacheWith respect to the management of flash storage, there is significant

value of having internal knowledge of the database’s functionality.

Database Smart Flash Cache

SGASGASGA

If not enough space in “Buffer Cache”, then write “Clean Block” to

“Flash Cache”

If not enough space in “Buffer Cache”, then write “Clean Block” to

“Flash Cache”

SGASGASGA

Access Buffer Cache -> Flash Cache

Hot DataHot DataHot DataHot Data

Warm DataWarm Data Warm DataWarm Data

Cold DataCold DataCold DataCold Data

2

Exadata Smart Flash Cache

Database Grid Servers

Storage Grid• 14x 2-socket storage servers

• 100 TB high-speed disk, or 336 TB high-capacity disk

• 5 TB PCI Flash• Smart Flash Cache holds hot

data• Over 1.5 million IO/sec from

SQL (8K)• Sub-millisecond response• 75 GB/sec query throughput

Exadata Database Machine

InfiniBand Internal Net

1 or 10 Gb Ethernet to Data Center

© 2011 Oracle Corporation 3

Database Flash Usage Models

Cache

Physical Disks

Logical Disks

Storage

DatabaseCache (SGA)

FLASH

FLASH

FLASH

FLASHDatabase Smart

Flash Cache

Exadata Smart Flash Cache

FLASH