If only some entities participate in a relationship then it is partial. Set EMPLOYEE is a generalization of the entity sets FULL_TIME_EMPLOYEE and PART_TIME_EMPLOYEE. STAFF inherits the attribute Salary of the entity set FULL_TIME_EMPLOYEE and the latter, in turn, inherits the attributes of EMPLOYEE. FULL_TIME_EMPLOYEE is a specialization of the entity set EMPLOYEE and is differentiated by the additional attribute Salary.
Database, which was assumed to be in a consistent state, will continue to be accessible. Compare shadow paging with log based recovery methods. Optimize the query write operation and X resides on thepage. Consider the schedule of three transactions T1,T2 and T3. DROP TABLE command deletes all the records along with the table definition.
To check this, it should be made sure that the XY scatter plot will be linear and that the residual plot will show a random pattern. A standard normal distribution table is utilized to determine the region under the bend (f) to discover the probability of a specified range of distribution. The normal distribution density function f is called the Bell Curve since its shape looks like a bell. Where X is a normal random variable, μ is the mean of X, and σ is the standard deviation of X. You can also find thenormal distribution formula here.
It represents the expenditure on those items which are shared by more than one activity and cannot be directly allocated to individual activity of a project. The range of coefficient determination from 0 to 1 hence provides the extent to which the dependent variable will be predictable. If the coefficient determination has a value of 1 will mean that the dependent variable can be easily predicted without any errors from the independent variable. A coefficient determination that has a value of 0 will mean that the dependent variable cannot be easily predicted from the independent variable. The concept of linear regression consists of finding the best-fitting straight line through the given points. The best-fitting line is known as a regression line.
→ A, either X is a superkey or A is prime. From the set of FDs we see that for all the FDs, this is satisfied, therefore, the relation is in 3NF. Describe the storage structure of indexed sequential files and their access method.
List two restrictions that are applied on the modification of base tables through view. Define check point and its impact on data base recovery. The schedule S is serializable does subway drug test if and only if the precedence graph has no cycles. Create a view Patient_visits where name is the name of the patient and times is the number of visits of a patient.
The simplest way to test if this assumption is met is to look at a residual time series plot, which is a plot of residuals vs. time. Ideally, most of the residual autocorrelations should fall within the 95% confidence bands around zero, which are located at about +/- 2-over the square root of n, where n is the sample size. You can also formally test if this assumption is met using the Durbin-Watson test. 2.Add another independent variable to the model. For example, if the plot of x vs. y has a parabolic shape then it might make sense to add X2as an additional independent variable in the model.
In this situation, performing checkpoints essential often will lead to better system performance. ISAM is a file management system developed at IBM that allows records to be accessed either sequentially or randomly . Each index defines a different ordering of the records. An employee database may have several indexes, based on the information being sought.