Operational databases are growing in size for many reasons.
There is the overarching trend of more and more data being generated every
year. But also, there is the growing need to store more data for longer periods
of time due to regulatory compliance issues (see previous blog postings).
As data volumes expand, it impacts operational databases in
two ways:
- additional
data stresses transaction processing by slows things down, and;
- database
administration tasks are negatively impacted.
In terms of performance, the more data in the operational
database, the less efficient transactions running against that database tend to
be. Table scans must reference more pages of data to return a result. Indexes
grow in size to support larger data volumes, causing access by the index to
degrade because there are more levels to traverse to return an answer. Such
performance impacts are causing many companies to seek solutions that offload
older data to either reference databases or to archive data stores.
The other impact, database administration complexity, causes
longer processing time and outages to perform such functions as backups,
unloads, reorganizations, recoveries, and disaster recoveries. In many cases the lengthened outages have
become unacceptable, causing companies to again seek ways to lighten up the
operational databases.
Even so, these
performance and administration issues are ancillary to the regulatory issues.
Although both are driving the need to move data from the operational database
into an archive data store, it is the legal requirements that have the biggest
impact in terms of data volume expansion.
One approach to
handling this growing problem is database archiving. For more details on database archiving, consult these previous blog posts: