Re: ORACLE7's Snapshot
Date: 27 Aug 93 09:48:41
Message-ID: <GHARRISO.93Aug27094841_at_jester.gssec.bt.co.uk>
In article <CCD7pH.CKp_at_nl.oracle.com> snieuwen_at_nl.oracle.com (Sandor Nieuwenhuis NL) writes:
Stuff deleted.
A snapshot is a read-only copy automatically derived from an SQL query on data from another database. (actually it can also be the same database) Data in the snapshot is maintained by Oracle7 and can be refreshed at a defined interval.
There is no limitation as far as I know to the number of users accessing the snapshot data.
Sandor Nieuwenhuijs
Oracle Netherlands
- These opinions (if any) are just mine. I do not represent Oracle ---
- Corporation in this Posting ---
It is probably worth mentioning that snapshots can be 'simple' where each row in the snapshot is based on a single row in a single table otherwise they are termed 'complex'.
Simple snapshots require that only data which has changed since the last snapshot is transferred between the two instances. With complex snapshots, all the data in the source tables is transferred every refresh.
Snapshots are also asynchronous. Synchronous data mirroring can however be implemented manually using triggers. Received on Fri Aug 27 1993 - 09:48:41 CEST