Databases Reference
In-Depth Information
Figure 13.15
RAID 5+0.
13.7.10 Which RAID Is Right for Your
Database Requirements?
Deciding which RAID strategy to use remains something of an art. However, the indus-
try does appear to be converging around specific usage. RAID 5 is the dominant strat-
egy for data stored within the database itself. It provides a reasonable balance between
striping redundancy and recoverability and cost. RAID 10 is used as well, somewhat less
commonly most likely because roughly half the disk is used for parity, making this a
robust but expensive alternative.
However, in addition to the actual active data of the database, such as the data, the
indexes, the materialized views, etc., the database designer needs to plan for the storage
needs of the recovery logs (transaction logs). The transaction logs are needed to recover
the database in the event of data corruption of disk failure on the devices storing the
active database data. The industry typically uses RAID 5, RAID 10, or RAID 1E for
transaction log storage.
13.8
Balancing Resources in a Database Server
Perhaps one of the least discussed but most practical problems of database server design
is the relative proportion of resources required within the server: relative amount of disk
storage, number of spindles, number and speed of the CPUs, RAM, etc. As a general
