Explain about the guard condition, Database Management System

Assignment Help:

What is a guard condition? Explain it with a suitable example.

The guard-condition is a Boolean expression written with respect to parameters of triggering event and attributes and links of object which owns state machine. The guard condition can also involve tests of simultaneous states of the current machine (or explicitly designated states of some available object); for case, "in State1" or "not in State2". State names can be fully qualified by nested states which contain them, yielding path names of form ''State1: State2::State3''; this can be used in a case where same state name occurs in various composite state regions of an overall machine.

 


Related Discussions:- Explain about the guard condition

Describe integrity and security, Describe integrity and security? a)   ...

Describe integrity and security? a)      Domain constraint b)      Referential integrity A value that appears in one relation for a given set of attributes also appear fo

A weak entity set and its identifying relationship, Q.  Define a weak entit...

Q.  Define a weak entity set and its identifying relationship. List the necessary conditions for a meaningful identifying relationship set of a weak entity set.    Entity is a t

Data dictionary, The database is to record information about artists for a ...

The database is to record information about artists for a (music) production company. An artist is the name of a singer or band; the name of the artist, the year the artist started

Discuss along with examples about several types of er model, Discuss along ...

Discuss along with examples about several types of attributes present in the ER model? Types of Attributes are: • SIMPLE attributes are attributes which are drawn from the ato

The first normal form (1nf), The First Normal Form (1NF) Let us first d...

The First Normal Form (1NF) Let us first describe 1NF: Definition: A relation (table) is in 1NF if 1.      There are no duplicate tuples or rows in the relation. 2.

Deadlock prevention, Deadlock Prevention One of the easiest approaches ...

Deadlock Prevention One of the easiest approaches for avoiding a deadlock would be to obtain all the locks at the begin of the transaction. Though, this approach restricts conc

What is system log, What is system log?  What are the entries?       An...

What is system log?  What are the entries?       Ans:  The system log that is generally written on stable storage contains the redundant data required to recover from volatile

What is indexed sequential file organization, What is indexed sequential fi...

What is indexed sequential file organization? What are the applications of this organization?  Ans: An index file can be employed to effectively overcome the problem of storing

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

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!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd