Oracle Distributed Processing Interview Preparation Guide
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Oracle Distributed Processing Interview Questions and Answer will guide us that an oracle distributed system consists of multiple autonomous computers that communicate through a computer network. Computers interact with each other in order to achieve a common goal. A program that runs in a distributed system is called a oracle distributed program, and distributed programming is the process of writing such programs. Learn Oracle Distributed Processing with this Interview Questions with Answers

12 Distributed Processing Questions and Answers:

1 :: Describe two phases of Oracle Two-phase commit?

Prepare phase - The global coordinator (initiating node) ask a participants to prepare (to promise to commit or rollback the transaction, even if there is a failure) Commit - Phase - If all participants respond to the coordinator that they are prepared, the coordinator asks all nodes to commit the transaction, if all participants cannot prepare, the coordinator asks all nodes to roll back the transaction.

2 :: What is an oracle SNAPSHOT?

Snapshots are read-only copies of a master table located on a remote node which is periodically refreshed to reflect changes made to the master table.

3 :: What is an Oracle SQL * NET?

SQL *NET is ORACLEs mechanism for interfacing with the communication protocols used by the networks that facilitate distributed processing and distributed databases. It is used in Clint-Server and Server-Server communications.

4 :: Differentiate simple and complex, oracle snapshots?

► A simple snapshot is based on a query that does not contains GROUP BY clauses, CONNECT BY clauses, JOINs, sub-query or snashot of operations.
► A complex snapshots contain atleast any one of the above.

5 :: How can you Enforce Referential Integrity in oracle snapshots?

Time the references to occur when master tables are not in use.
Peform the reference the manually immdiately locking the master tables. We can join tables in snopshots by creating a complex snapshots that will based on the master tables.

6 :: What is an oracle snapshot log?

It is a table that maintains a record of modifications to the master table in a snapshot. It is stored in the same database as master table and is only available for simple snapshots. It should be created before creating snapshots.

7 :: What is Oracle Two-Phase Commit?

Two-phase commit is mechanism that guarantees a distributed transaction either commits on all involved nodes or rolls back on all involved nodes to maintain data consistency across the global distributed database. It has two phase, a Prepare Phase and a Commit Phase.

8 :: How can we reduce the network traffic in Distributed Processing?

► Replication of data in distributed environment.
► Using snapshots to replicate data.
► Using remote procedure calls.

9 :: What are the various type of snapshots in Oracle?

Simple and Complex Snapshots

10 :: What are the options available to refresh Oracle snapshots?

COMPLETE - Tables are completely regenerated using the snapshots query and the master tables every time the snapshot referenced.
FAST - If simple snapshot used then a snapshot log can be used to send the changes to the snapshot tables.
FORCE - Default value. If possible it performs a FAST refresh; Otherwise it will perform a complete refresh.