What is the function of the Data Manager ?
The Data Manager is a DB2 component
that manager the physical databases. It
invokes other system components, as
necessary, to perform detailed functions
such as locking, logging, and physical
I/O operations (such as search, retrieval,
update, and index maintenance).
What is cursor stability ?
It is cursor stability that “tells” DB2 that
database values read by this application
are protected only while they are being
used. (Changed values are protected
until this application reaches the commit
point). As soon as a program moves
from one row to another, other programs
may read or the first row.
What is meant by concurrency ?
Concurrency is what allows more than
one DB2 application process to access
the same data at essentially the same
time. Problems may occur, such as lost
updates, access to uncommitted data,
and un-repeatable reads.
What will the COMMIT accomplish ?
COMMIT will allow data changes to be
permanent. This then permits the data to
be accessed by other units of work.
When a COMMIT occurs, locks are freed
so other applications can reference the
just committed data.
What is a clustering index ?
It is a type of index that (1) locates table
rows and (2) determines how rows are
grouped together in the tablespace.
On the create tablespace, what
does the CLOSE parameter do ?
CLOSE physically closes the tablespace
when no one is working on the object.
DB2 (release 2.3) will logically close
tablespaces.
How many buffer pools are there in DB2 ?
There are four buffer pools: BP0, BP1,
BP2, and BP32.
What is a buffer pool ?
A buffer pool is main storage that is
reserved to satisfy the buffering
requirements for one or more
tablespaces or indexes, and is made up
of either 4K or 32K pages.
What is JMS?
JMS is an acronym used for Java
Messaging Service. It is Java’s answer to
creating software using asynchronous
messaging. It is one of the official
specifications of the J2EE technologies
and is a key technology.
What is the difference between ic
and queue ?
A ic is typically used for one to many
messaging i.e. it supports publish
subscribe model of messaging. While
queue is used for one-to-one messaging
i.e. it supports Point to Point Messaging.
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