Oracle file group repository overview
Oracle Database Tips by Donald Burleson
Question: I want to
make incremental backups every night and track the relative
generation of my backup data files.
I remember that IBM mainframes had
generation data groups (GDG's), and I need to find a similar
tool for Oracle where I can treat a groups of related files
together and track their relative generation. What is the
equivalent if a GDG in Oracle, for tracking generations of
related files? I know about the RMAN retention
Starting in 10gr2 we see
a push toward information provisioning tools and the new "file group repository" features which is very similar
to a GDG, especially for the versioning of related datasets.
The new file group repository (FGR) allows you to create
groups of related data (using the DBMS_FILE_GROUP package) and
then track and version the data.
This allows the Oracle DBA to use
the file group repository to create incarnations of related
files and manage them over time, as a single unit, dubbed a
The Oracle documentation on information provisioning notes that
the file group repository has special uses for Oracle Streams:
"Some data must be shared as it is created or changed, rather than
occasionally shared in bulk.
Oracle Streams can stream data between databases, nodes, or blade farms in a
grid and can keep two or more copies synchronized as updates are made."
Oracle docs on information provisioning note the file group
repository architecture with this simple example"
"In this scenario, a business sells books and music over the internet. The
business runs weekly reports on the sales data in the inst1.net database and
stores these reports in two HTML files on a computer file system.
The book_sales.htm file contains the report for book sales, and the
music_sales.htm file contains the report for music sales.
The business wants to store these weekly reports in a file group repository
at the inst2.net remote database.
Every week, the two reports are generated on the inst1.net database,
transferred to the computer system running the inst2.net database, and added
to the repository as a file group version.
The file group repository stores all of the file group versions that contain
the reports for each week."
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