HP Large Objects System Management Manual

HP Large Objects System Management Manual – 543599.001
9. Stores the next part of the object, for example to store the next 20 MB of the
object content:
buddytest put grp01 -3931360999717732352 object3 10000000 20000000
10. Stores the final part of the object, for example, to store the final 10 MB of the
object content:
buddytest put grp01 -3931360999717732352 object3 30000000 10000000
11. Retrieve the first half of the object, for example, to retrieve the first 20 MB of the
object and store it in a file called object4:
buddytest get grp01 -3931360999717732352 object4 0 20000000
12. Retrieve the last half of the object, for example, to retrieve the last 20 MB of the
object and store it in a file called object5:
buddytest get grp01 -3931360999717732352 object5 20000000 20000000
13. To test that your Large Object environment is functioning correctly, concatenate
the two retrieved object files to get the original content:
cat object4 object5 > object6
14. Verify that object6 has the same content as object3:
diff object3 object6
3 The Large Object scheme
3.1 SQL Store Concepts
See Appendix C for an Entity Relationship Diagram showing the Large Object SQL
database. The sections below describe the major components of the Large Object
scheme in a top down approach.
3.1.1 BuddyGroup
A BuddyGroup is the top level of the database hierarchy. It is usually a large area of
storage, typically all the Large Object storage for a node. Many BuddyGroups can
exist on a node, but a single BuddyGroup may not span multiple nodes.
Each BuddyGroup is assigned a five character name which is used by application
programs for reference purposes. An application stores and retrieves objects by
referencing a specific BuddyGroup name.
3.1.2 BuddySet
A BuddySet is the next level of the database hierarchy below a BuddyGroup. A
BuddySet exists on a single subvolume, and there can be many BuddySets per
volume. A typical implementation contains a single BuddySet per volume.
3.1.3 BuddySpace
A BuddySpace is the next level of the database hierarchy below a BuddySet. A
BuddySpace is a single large unstructured Enscribe file. The file size depends on how
the Large Object system is configured, but a single Buddy Space file is in excess of
1GB. The number of BuddySpaces in a BuddySet is determined by the parameters
104 BSET_MIN_SEG_SIZE and 105 BSET_MAX_SEG_SIZE, as there must be at
least one BuddySpace for every power between the two values. Additionally, there
may be multiple BuddySpace files for a given power in a BuddySet. The number of
BuddySpace files per power depends on the range of objects to be stored. For
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