What is static/global variable in computer process?

.1. How pipeline promotes parallel processing?Explain with examples.2. Mention the Hardware issues involved in parallel processing? 3.Give the purpose of having buses in distrubuted parallel processing?

A  distributed  database  is  a  network  of  databases managed by multiple database  servers  that  appears  to a user as single logical database. The data  of  all  databases  in the distributed database can be simultaneously accessed and modified.

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 ...

Snapshots and SNAPSHOT LOGs

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.

A  snapshot  log  is a table in the master database that is associated with the  master  table.  ORACLE uses a snapshot log to track the rows that have been  updated  in  the master table. Snapshot logs are used in updating the snapshots based on the master table.

SQL  *NET  is  ORACLE's  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.

 Simple and Complex.

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

 Snapshot is an object used to dynamically replicate data between distribute database at specified time intervals. In ver 7.0 they are read only.

      -  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.

 Updating or Inserting records in remote database through database triggers. It may fail if remote database is having any problem.

 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.

 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...

 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.

 We must be able to create a after row trigger on table (i.e., it should be not be already available) After giving table privileges. We cannot specify snapshot log name because oracle uses the name of the master table in the name of the database objects that support its snapshot log. The master table name should be less than or equal to 23 characters. (The table name created...

 Database on other servers can be updated and those transactions can be grouped together with others in a logical unit.Database uses a two phase commit.