A no-force policy is used in transaction control in
database theory
Database theory encapsulates a broad range of topics related to the study and research of the theoretical realm of databases and database management systems.
Theoretical aspects of data management include, among other areas, the foundations of q ...
. The term no-force refers to the disk pages related to the actual database object being modified.
With a no-force policy, when a
transaction commits, the changes made to the actual objects are not "forced", that is, required to be written to disk in-place.
A record of the changes must still be preserved at commit time to ensure that the transaction is
durable
Durability is the ability of a physical product to remain functional, without requiring excessive maintenance or repair, when faced with the challenges of normal operation over its design lifetime. There are several measures of durability in use, ...
. This record is typically written to a sequential
transaction log
In the field of databases in computer science, a transaction log (also transaction journal, database log, binary log or audit trail) is a history of actions executed by a database management system used to guarantee ACID properties over crashes ...
, so that the actual changes to the database objects as recorded on disk can be written at a later time.
For frequently changed objects, a no-force policy allows updates to be merged and so reduces the number of write operations to the on-disk database object. A no-force policy also reduces the
seek time Higher performance in hard disk drives comes from devices which have better performance characteristics. These performance characteristics can be grouped into two categories: access time and data transfer time (or rate).
Access time
The ''access ...
required for a commit by having mostly sequential write operations to the transaction log, rather than requiring the disk to seek to many distinct database objects during a commit.
References
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Database management systems