Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
What is a transaction?
The Transaction is a unit of data processing. For instance, many of the transactions at a bank may be withdrawal or deposit of money; transfer of money from A's account to B's account etc. A transaction would include manipulation of one or more data values in a database. Therefore, it may need reading and writing of database value. For instance, the withdrawal transactions can be written in pseudo code as:
Example:
; Suppose that we are doing this transaction for person
; whose account number is X.
TRANSACTION WITHDRAWAL (withdrawal_amount)
start transaction
IF X exist then
READ X.balance
IF X.balance > withdrawal_amount THEN
SUBTRACT withdrawal_amount
WRITE X.balance
COMMIT
ELSE
DISPLAY "TRANSACTION CANNOT BE PROCESSED"
ELSE DISPLAY "ACCOUNT X DOES NOT EXIST"
End transaction;
Another same example may be transmitting of money from Account no x to account number y. This transaction may be written as:
What are the General Transformation Rules for Relational operations? Ans: The transformation rules transform one relational algebra expression to AN EQUIVALENT ONE 1. E
What is a Linked Server? Linked Servers is a method in SQL Server by which we can add other SQL Server to a Group and query both the SQL Server dbs using T-SQL Statements. With
What are the two integrity rules? Ans: The two integrity rules are: Entity Integrity Rule & Referential Integrity Rule. Entity Integrity Rule - If the attribute A of rel
What is transaction? Collections of operations that form a single logical unit of work are known as transactions.
What is serializability? Explain its types? The data base system must control concurrent implementation of transactions, to ensure that the data base state remains consistent.
Question: Consider the following database relations for a textbook ordering system used by a college bookshop: Book (b-copy#, bname, ISBN#, author, price, subject) Order (s#
What are wait-for-graphs?Give the algorithm to construct a wait-for-graph from a given schedule of transactions? How can deadlocks be detected from wait-for-graphs? Ans: The
Define Thomas write rule Thomas' write rule: The Thomas' write rule is a modification of timestamp-ordering protocol for concurrency control. Assume that transaction T i issue
What are uncommitted modifications? The immediate-modification technique permits database modifications to be output to the database whereas the transaction is still in the act
Design Of Distributed Databases: The distributed databases are mainly relational at local level. So a local database schema is the similar as that of a centralised database design
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd