 Assalamu alaikum dear students today we are in the lecture number 12 of the database management system course the course code is CS403. In the previous 11 lectures we have covered 2 phases of the database development process which are the preliminary study or the initial study and the analysis phase. The purpose of the preliminary phase is preliminary study phases to understand the working of the existing system and the purpose of the analysis phase is to design the database after analyzing the requirements of the users. Today's lecture we will cover both of these phases that is I will give you an example case and try to explain to you how do we apply these phases in the real life example. You must remember one thing that we that I told you in the beginning that the proper application of the process this is not the main objective of this course you study those phases the application of those phases in another course and that is basically software engineering you study one or two courses of software engineering in different CS programs. The objective of this course basically is to study the tools and the concepts that are the concern of the database that is the ER data model that we use for the concept of the design and the relational model that we are going to study in the next lectures. In today's example I will give you an idea how do you apply these phases in the real life example but mind it these phases they are suitable for a medium level a small level scale system for a large scale system you need more tools you need more depth study of different techniques to analyze a system. So let us start today's lecture today I will explain to you how do we apply how do we use the ER data model in a real life example. We study an example scenario and apply the design phase we have studied so far not only the design phase rather the initial study phase and the design phase and as I have mentioned you before that the design phase concerns the design of the conceptual database design as well as the logical database design. So in today's example we will be concentrating only on the conceptual database design because that involves the ER data model. So let us see what system we are seeing we are studying the examination system of an educational institute it is a general system you cannot say that it would be applicable to any educational institution no there could be variation rather there will be variation almost everywhere but this is a general system this is how it generally works in different educational institution especially the institution that are offering graduate or post graduate courses and that are based on the semester system mind it this is not the annual system this is the semester system. So I will try to explain to you the working of the semester system as well I hope most of you are familiar with that because you when you are studying this course you are also studying it on the basis of semester system. So let us see what we are discussing during the initial study phase of the system we studied following major points see the detail could be there could be so many details of this thing but I will try to mention the major points that could explain you the working of the system the preliminary study. So in this examination system students are enrolled in programs or decrease for example you go to the institute and say I want to do let us say BCS MCS or any other degree in that institute and obviously that is based on the semester system. The program the degree that you want to do is it is based on different courses if you are doing the BCS obviously you know it is a 8 semester course 4 years it generally spans 4 semester 4 years and in each semester you enroll different subjects so different courses are offered at the start of the semester like when you start semester 1 there is a certain list of courses that are offered by the institute you will study these courses during first semester when you are enrolling in the first semester obviously there will be some class that would be in a second semester obviously there will be a class that should that may be in the third semester and it goes up to the 8th semester so at the start of every semester for each degree let's say is it MCS or MBA or BCS or BC any degree for every degree depending upon the number of semester it consists of the courses are offered for every semester let's say we offer these six courses for semester 1 of BCS these five courses for semester 2 of BCS and like that so at the start of each semester certain courses are offered for each semester of every degree moreover students enroll these courses at the start of every semester see there's a difference between courses being offered and courses a particular student enrolls rather there's there's another concept the courses in a program so basically there are three things that we studied here one thing one thing is that this program consists of these courses and out of those courses some of them could be compulsory and some could be optional so it depends upon the institution what optional courses they may offer one thing secondly it also varies sometimes that in a particular semester one course is offered let's say in third semester and next time the same course may be offered in the let's say fourth or fifth semester so the semester in which a particular course is offered it may vary from semester to semester so there's one thing that this course comprises of these courses second other thing is that in this semester we are offering these courses for these semesters and thirdly each student will enroll his or her courses but why is the difference between the courses offered and the courses enrolled because the students enroll courses depending upon their individual situation for example there's a course b and to study course b you have to pass the course a it means if a course a if you are not passed in the course a god forbidden then definitely in the next semester you will not be able to register in the course b so in the next semester well maybe a rest of your class is registering the course b you will not register the course b because the course b has got a prereq that is the course a so in the next semester you will be you will be registering the course a whereas the students who have passed that the course a they will be registering other courses plus the course b so it means that the the the courses a program consists of the courses offered in each semester and the courses a particular student registers they are different things I hope the difference is clear to you after valid registration I hope now you understand what do we mean by the valid registration because as I as I explained to you that every student can not enroll in all the courses that are being offered in a particular semester because depending upon its individual situation so once the courses have been enrolled classes start the students attend the classes as per their schedule as per the courses that they have registered and obviously teacher start taking the classes so each course is offered and that is also assigned to particular teacher now teacher start taking classes and you might be familiar with the thing that they are different exam during this semester and that we call the mid-term exam there could be one mid-term exam or two mid-term exam or maybe three so there are some institutions that offer three mid-term exam but and consider two the best ones but in our this example system only one mid-term exam is taken and the other one is the final exam apart from this mid-term exam and final exam there are also sectional marks these are the marks that are granted to the students on the basis of different activities like assignment quizzes that are given to the students that in each teacher gives to the class and student how they perform in that in those activities quizzes or assignments they are marked and ultimately your result is calculated on the basis of your mid-term exam on the basis of your final exam and also on the basis of your sectional performance so this is how the system works then the students grade points that we call GP grade point is calculated in each subject and obviously based on the performance three things mid-term exam final exam and the sectionals then there is a grade point average GPA semester GPA is calculated on the basis of subjects gps the subjects see the digital grade points and you say this is the semester GPA semester's grade point average then we have C GPA cumulative grade point average obviously you have GPA of the individual semester and the overall GPA that represents your performance in the course or in the degree that is called C GPA so you have every semester GPA and obviously when you are in first semester so GPA and C GPA same thing obviously you have second semester you have got the GPA of first semester you have got the GPA of the second semester but there is a C GPA that is calculated on the basis of GPA of first semester and the GPA of the second semester so that is called the C GPA then it goes up to the last semester and finally you've got a certain C GPA that is your grade point in your entire degree courses results students that are these different things they are stored in files in permanent storage files now we also discussed with the users what type of output they require from the system the first thing is what are the users what are the different users or what are different user groups that are involved in this system students this is one user group the teachers this is second user group then the controller and then obviously the parents may be users but parents and students you can consider same unless students do not give them the result that they want to sign with their father go outside and sign and take it back otherwise so to be brief we consider parents perspective and students as the same then obviously apart from the controller there are definitely the administration like your principal or your chairman these are also the people that want different reports from the system so teachers and controllers they need class list or attendance sheet they want to see what students are enrolled in a particular subject so that is also used by the teachers as attendance sheet this is a class result in an individual subject and overall in all subjects all students have a result the students need transcripts transcripts are the final degree which has a detailed mark sheet that is a transcript and then depending upon the requirement any student may ask for a semester card that they want to see or want to use it somewhere anyway in addition, the students want to see the subject result as well so this is something that I have talked about you may have guessed that what is our system how does it work and what is the expectation of the users now how do you know these things one thing is obviously from the users of that system with the controller of the examination with the principal chairman with the students everybody one thing is that you understand the working of the system from different perspective how do the students see it how do the doctor and the chairman and the principal sees it how do the controller how does the controller see it see actual person actual people who are responsible or whose explanation you should rely on that is basically controller office but still you would like to see the you would like to know the comments of the people other people as well other users as well so you consulted different users to know to understand the working of the system secondly each user each of these users they have got their own interest their own requirements from the system so definitely to develop the system you need to know their perspective their requirements their interest in the system so you discussed with each of them each user group and then you established an understanding of your own about the system but as I told you rather than just keeping it in your mind rather than putting it in the paragraph form writing rather than writing it in the text form you should better represent your understanding of the system and the form of a graphical tool because the graphical tool the graphical symbols they have got the precise meaning so there is no chance that one thing you are interpreting in one way but other one is understanding in another way so we you must you might be remembering that we discussed that the tool used that for this purpose is the DFT data flow diagram and there are three types of DFTs context I will not end detail so let's work with the DFTs data flow diagrams this is our context diagram as you be remembering that the context diagram is basically the relationship of the system with the external entities and these external entities could be any person thing place department or another system so we have represented we have drawn this context diagram in front of you and the center is a big bubble that is representing the system and we have written the name of the system in the in this big bubble and that is the examination system then you see we have represented four different external entities in this context diagram one is student controller teacher and registration system as you can see the registration system as such has also been shown as an external entity whereas the student there are many students but they are persons teacher or they are people human being controller person human being but the registration system it's a system but because that is providing something to our examination system that has been shown as the external entity in this context diagram then you can also see different data flows from and to different external entities from and to the system for example if you see registration system the registration system is giving the personal details of the students not only students the valid students and what do we mean by the valid students we mean the students who are still enrolled or registered in our institute so this is an activity that is the responsibility of the registration system that the students who are enrolled here who are on the register who are registered with the institution the registration system it will keep the data of those students obviously the exam system will like to know will need to know the valid registered student because invalid student or unregistered student they should not be allowed to register in any class or in any course so this is data this is something that we receive from the registration system then teacher gets class list from the examination system what are the students that are in a particular class that the teacher gets from the examination system and other thing is the teacher submits the result it's not the final result mind it calculating the final result is not the job of the teacher this is the job of this is an activity this is a process that is performed by the examination system so what is the responsibility of the teacher in the semester system teacher teaches the class it takes different exams 1 2 or 3 midterms then it gives different quiz assignments evaluates them and it gives the results of individual pieces like it gives the result of the midterm exam it gives the result of the session marks including all other activities and finally it submits the final exam result all these pieces are entered into the database or are they are given into the examination system and then examination system whether they do it manually or they do it using some tool or computer but the responsibility of the examination system is that it will calculate the result on the basis of data that is provided by the teacher this is not the final result this is those individual items individual pieces that are provided by the teacher to the system and then the system the examination system that calculates the result the final result and then there is a controller external entity controller is provided by the class result of obviously each class controller is also provided by the subject result and also the overall result of the entire class I think there is something missing we should also show the subject result to the teacher as well anyway you can add that then the student student the data the activity that that the student provides to the system is that it enrolls it registers the courses with the system this is the data that is that flows from student to the system and then upon the request examination system provides the final result either it could be the subject wise or it could be the entire semester result or other thing like transcript or semester card they are also provided to the student by the examination system so this is our context diagram I hope you are clear about it the next diagram is the level naught diagram as I told you before that level zero diagram is the most important diagram and every DFT that you contain it must contain at least both the context and the level zero or if you want to be further precise when it must contain the level zero diagram because level zero diagram is the description of the entire system is the description of the working of the entire system so now we are moving towards the level zero diagram so let us see how do we build that as I told you the approach of building the level zero diagram it is a traditional approach of divide and conquer you need to identify different major modules in your system for example in our case we identify three major modules in our system and they are the subject registration one second result submission and obviously this result submission means result submission by the teacher to the system and thirdly the result calculation we identified these three system and then the approach they will use that we will use to develop the level zero diagram is that we will represent these modules individually and one by one we will build them and ultimately our diagram will be completed so let us see how do we do that now in this diagram this we have drawn the module one of the of our examination system here you can see that first of all the activity initiate from the externality student it gives a the registration detail in the form of a form so for the first process in this module is to edit the form editing form means that the person checks whether the form has been filled in properly all the entries are there it has been signed properly etc these things are checked in the edit form process once the editing has been finalized or once the form is validated then form is transferred to the next process that says check pre-rex pre-rex I have told you that certain subjects have pre-rex pre-requisites means if you want to read the database if you want to enroll in the database management system it is necessary for you to do such a one that has been read or you say that if you want to read the data structures then it is necessary that you have the programming language course or the intro to programming course that you have passed because you have the data structures in it all the concepts are used in the same way if you want to read the operating system then it is necessary that you have passed the data structure because the operating system uses its conceptions so what happens is that if you have not cleared the course of programming language then you cannot enroll in the data structures and if you have not enrolled in the data structure then you cannot enroll in the operating system that means that something very funny things happen in the special system that your class fellows will read the course of the fourth stage and sometimes you do not say that a student is also on the first or second stage so it happens in the special system it has its beauty but it has its complexity so not in every course but in many courses like in the next semester there are many courses of pre-rex so our process 2 is its objective or its purpose is that it checks the pre-rex in which in the courses the student has applied can it really apply in the courses and mind it from here we are supposing that the student we have met is a valid student because we got the data from the registration system it has been confirmed that this is our valid student this is our exam system the concern of the exam system is to check the validity of the courses that is applying she is applying so here we have a pre-rex check when you want to check the pre-rex so obviously you need to know that what are pre-rex for a particular course if there are any so in that case you cannot remember all of them and rather you don't need to do that your data store if you do not have a database then in any file in any file where this data will be written that what are the pre-rex of any subject you will also consult and from there you will see that in the courses applied by the student these are the pre-rex and for that you will also have to see the pre-rex for that see here your result store the result of your data store is also giving you a result which means that from there its previous result they are verifying they are verifying that whatever the pre-rex of different courses it has been cleared during the previous semester so for that you get the pre-rex data from the program and course data store and for the clarification of whether the student has cleared all the pre-rex or not for that you need the previous result and that you are getting from the result data store if all the courses that students has applied for if the student is eligible for them then you will verify the registration of the student and you will store that information your registration or enrollment data store and you will also notify that to the student as well so here we have shown only the invalid invalid means if the student cannot enroll in a particular student because he is not cleared he is not cleared the pre-rex then you will form the student that you cannot enroll in these courses and the student will again come into this process he will take another form he will fill in again and he will once again enter into this process unless he enters or he submits a valid form I hope you are clear about this particular module of your example system let us see the next module here I have basically put in the background the our previous module it is there on the diagram but in just to maintain your focus properly I have put it in the background now our focus is on from the process four now this module is regarding the submission of the result teacher submits the result in the process number three and by result I have already explained to you by result we mean the individual results of the midterm of the session of the final then this result is passed on to the process four that is the calculate GP and from there the subject GP is calculated and the results are updated in the result data store so this is the second module that we are basically the teacher submits the result and the result of the individual subject is basically calculated now in this diagram in this screen we have again put the previous two modules in the background and just to highlight the most recent one the third module that is the calculation of the final result so we start from the process six process six takes the registration information from the registration data store and it also takes the individual subjects result from the result data store because now you are basically first focusing on the calculation of the GPA and the CGPA there is a formula there is that is a bit complex say we do not need to understand that right now to calculate the grade point average and the CGPA here we have only shown the calculation of the GPA and the CGPA as the processes and we can enter the detail of these processes into the detailed diagram if you want to make detailed diagram of these process then we can do that but the thing is here our objective is not to go into the detail as objective is to explain to you how do we apply different processes so in our example system example scenario we will not go into the detail rather we will restrict ourselves up to only the level not diagram so here on this screen you are seeing the entire level not diagram and you can see how different components of the this diagram are linked with each other and you have also seen that we have different modules say how to identify and how we draw them and when they are from a point point whether they are linked to a data store basis or through a process so overall you get a complete diagram that explains your whole system now the thing is that you are looking at any of these processes at this time you are looking at your level not diagram any of these processes details can be made that means you are seeing that the number of processes given in all of these is 1.0, 2.0, 3.0 because this is a level not diagram now for example if we want to draw the detail of let us say calculate CGPA that is the process number 7 so when we make its details then 7.1, 7.2 and like that or even if we have 7.1 when we will do its details then 7.1.1 and like that so this is our example examination system we have a complete level zero diagram you can watch it and see how we have represented the description of the system Dear students, what we have done so far is that I have explained the system working in front of you and I have drawn it using the DFT the tool and why do we do the DFT to get the precise working to precise understanding of the system now apart from this as we have mentioned before that we can also use another tool in this which is our initial study phase which is cross reference table that also helps you ultimately towards your design so let us see how we can draw cross reference table for this example scenario in this cross reference matrix we will do that we will see that the requirements of our users that will come against the items or attributes or properties that will come against them we will relate them to what output we want or which item will come against it the cross reference matrix if you see in this then the reports required in the columns from different users and different type of users we have already mentioned that which users of our system are so column wise if you see then here you see different reports and requirements of the users and in the row we have called those attributes or those properties that are placed that which which report will come and when we have ticked the cells that we have put the mark on it that means in which report which item is coming for example if you see in this then in the column we have the first thing that is written in the first thing we see in the reports that is the transcript the transcript that means the one that a student wants when he completes it at that time which he has a result card on the detail on which it is written that is the transcript that is one requirement apart from this we have semester result card that is a student who has a particular semester in which if he has a degree of 8 semesters then after 3 semesters after 4 semesters at any time if he wants his previous semester result card then he or she can apply for the semester result card that we will call semester card. Obviously one thing that the teachers want and apart from that the controllers, the chairmen and the principal want that attendance sheet. The thing is that in every class all our students are there you have to get all the attendance lists so that they can get a cross reference in this sense that one thing will happen that we have so many students in this class who are they and the other thing is that you can also use that document as the attendance sheet. So this is the thing, apart from that the class result is subject wise that in every subject and when we talk about subject or result then it is our wish that about every subject that the number of the exam, the number of the final marks, the number that you have allocated, for example there is a paper of 100 number in which you say that we have given the 25th number to the midterm exam, we have given the 25th number to the sectional activities and we have given the 50th number to the final exam activity. So this will make your result that in the 25th the number of the midterm exam will come. All the activities that your assignment courses have, their number will be evaluated in your session and the performance in your final exam that will be evaluated out of 50 and it will be placed here. So that will be called the class result subject wise. So that gives you a detail of a subject, individual subject that a student has performed in every subject, component wise. And apart from that obviously there is a class result. What does a class result mean? It means that the overall result of a class, that is every student's performance is subject wise. If a student has a role in six subjects, then on this report we do not have the details of subjects, we have the class result subject wise. In this we have that this student has studied this subject, there are so many marks, this is its great point. This subject has studied, there are so many marks, this is its great point. So let us say that a student has done five or six subjects and a role. So that is the column in which the student's name is in the row. So after giving the overall performance of each subject, the final column will contain the GPA. GPA means that it has a great point average in this semester. And the next column in which it can be called the CGPA. That if this semester it has a GPA and the previous semester it has a CGPA, now this is the CGPA of the system. So this also needs a report that obviously it needs the controller, the chairman, the principal and the teacher as well. What is the class performance? If you look at the row wise, we have written different attributes here. And for the convenience in the cross reference, we have placed the names of the attribute in the alphabetical order and it is in ascending order. For example, first of all the course name. The course name that has been ticked is in the transcript, in the semester result card and in the class subject result. And the course name means that what is the name of the course? Apart from that, if you look at the cumulative GPA, the CGPA is coming in the transcript, the semester result card is coming in and the overall result of the class is coming in. If you look at the date, the date will be on almost all of the class. If you look at the father name, the father name should be in the transcript and the semester result card should be on it. In the same way, you can see that all the attributes are there, if you look at it later, in the same way, we have done all the attributes and properties of the course name. We have done all the different types of the attributes, in which we can see which attributes are required on which report. What is the purpose of this? What is the purpose of creating a cross reference stable and cross reference matrix? These are your two things, your DFT and your cross reference matrix. By combining these two, you will try to establish your ER diagram, because the ER diagram, the ER database design, it contains the entity types, their attributes and the relationship between them. One more thing is that when we said that we have different relationships and our cardinalities, then for the cardinalities, you have to question the users. From there, you will be able to understand how and how to show the relationships and their cardinalities. Let's see how we can use these two things in the ER diagram. We have done different activities in our preliminary study phase or the initial phase. Now we have moved to the analysis phase and for this, we have two things for this phase. We have done some points in the course note and some of the precise forms we have are DFT and cross reference matrix and cross reference table. The first activity we have to perform in the ER database design or conceptual database design is that we have to identify what are the entity types that are required, that we should represent in our database design. Now the first thing is how we can identify them. First of all, the resource we take, which we refer to, is our DFT. And especially in our level note diagram. So if we look at the level note diagram, from where we have these students, the controller, the courses and the teachers. These four are the external entities that have been represented there. So we have placed them here as such. Other things we have here, we consider them as the candidate entity types because they were basically the data stores. For example, we had courses offered, programs, registration. These are basically the data stores. So we consider them to be our candidate entity types. Now if you look at the registration area, then there can be an activity here and there can not be any activity here. Why? Because we have assumed that we will get the registration data from the registration branch. So we have to know the value of our students. The registration here, this means that registration when we say that students have enrolled in a particular student. So it is called registration or enrollment. The real thing is that you have to understand that this is the registration area. Another thing I would like you to pay attention to is about the controller. When we started reading the ER data model, I told you that there is a difference between the external entity in the DFT and the entry type in the ER data model. Now look, the controller is an external entity in the DFT. Why is that? Because we have defined that anything that provides data to the system or it accepts data from the system, it is an external entity in the DFT. So the controller is a part of that system. It gives different commands to the system. It takes different things from the system. So the controller in the DFT it has been represented as an external entity. But the thing is that your ER database design it will not appear as an entity type. Why? I explained this to you in detail that although, as you can see here, the ER data model or ER design of your entity types most of them you have adopted from your DFT, level of diagram. But in this kind of situation, in this kind of special cases, you have to be careful about that. You will not represent the controller as an entity type in your ER database design. Why? Because there is always a single controller in an examination system. So when I told you that there is a single instance of this thing the entity type for which the instance is single and it is understood, assumed. So most of the time, you do not represent it in the ER database design. There can be exceptions anywhere. But most of the time, as a general rule the single instance of this entity type and assume that it has to play this role will not represent as the entity type in your ER database design. So you will see that if we have the entity types written on the screen we will exclude the controller from them. Similarly, the results are different forms of results. So all those results can be entity type. But it can be a specific result or a specific place. We will see how they represent us. Cross reference table will help you identify the entity types through your abstraction process and the relationship between them and the link will help you identify them. See how it will help you. It will help you that when you see that there is a report we need to know logically speaking or system analysis or if you use your abstraction process should all those things be represented as a single thing and they appear to be belonging to different things. Secondly, if we establish that these entities belong to entities then at least your cross reference matrix will definitely tell you that these things are linked to each other. If you look at the example first we will talk about transcripts. If you look at transcripts there are course names cumulative GPA date father name student name program name if you look at the registration your transcript will have the result of every semester and the overall result since you have logical grouping some things which are related to the student's personal data i.e. his name father name registration number some things which are related to the subject he had enrolled or read with him so when you identify the entities from your DFD in front of you then this will show you or give you another strategy give you another reason that you group these attributes because logically some students belong to personal data then you associate those attributes with the student and look at this right now we are just focusing on our diagrams otherwise when you have discussed with the users you can establish from there so this can happen from there but at this time if you just focus on your diagrams then they are also guiding you that DFD has told you that these are the possible you have discarded something from there due to the reason from here when you have seen the reports you have also seen that there are some different properties if you start grouping them then you will be able to see which properties are our identified entities they will be placed and the first thing if someone was missing from there from here you see some properties that you can't associate with them then you can make a new entity otherwise if you have a cross reference matrix it will support those entities that you have defined from yourself or from DFD or you can also define them in BAS cases and the second role that I mentioned earlier is that it helps you to identify the link, the relationship between different entities there can be another strategy and that is that this strategy can be but you don't adopt that what we have said earlier you better follow that there can be a strategy that you can represent the reports as entity types but you will see that later we will read functional dependencies that will help you to decompose them if we look at this diagram here we have 1,2,3,4,5 reports if we suppose these 5 are our entity types and the attributes that you associate with each attribute you will see that this is one thing but later on functional dependencies that is why I am telling you don't adopt this it will help you to split and divide and ultimately you will reach the same entity types that you have identified from the previous approach they will be almost the same there may be a difference but ultimately they will be almost the same that means you can adopt any approach the diagrams they help you to identify different entity types their associated attributes and also the relationship between them if you look at the attendance sheet if you look at it the program name the semester number if you are confused what do we mean by the semester number the semester number it can be taken in 2 meanings the first one is what is the semester the first semester the second one the second meaning is the particular identification we normally use the semester identification in the semester system we divide it into 2 fall and spring the semester will start in January we call it spring and what will start let's say from September fall the semester's view name is fall 04 means the fall semester of 2004 the current semester is fall 2004 if we say spring 2003 that semester which started in January and went to June that is spring 2003 the semester name is the unique identification of a particular semester like summer 2002 fall 2002 fall 2001 like that when we say semester number the particular semester in which a particular student right now is it's semester all of its semesters in this way as we said you have to identify your entry types from your DFD and after that you have to refer to your cross reference matrix and from there you have to associate your entry types and then you have to identify the relationships again and again that is you have to be objective that all of your requirements are somehow being fulfilled and your DFD and your cross reference matrix which concludes your achievement which you have identified from your DFD in any way as I have told you that should be supported by your cross reference matrix Dear students so far you have seen how we have our DFD we identify different entry types after that when we look at cross reference matrix we verify which of them are valid entry types after that we identify which of them should be associated with which entry type in this next phase is you have to draw different entry types again your interviewing, your mind, your notes or these two diagrams and in that we will adopt the approach and then we will divide and conquer it that is first we will associate the attributes with them after that the same entry type or any other entry type that is involved will show their relationship and we will draw this diagram in parts because you have a lot of entry types involved in the diagram so if you want to show all the entry types on one page then your diagram it may get very complex but when you are making it in parts in small screen you can see all the attributes but when you draw a complete diagram in that you can only show entry types and their relationships and their cardinalities and as far as attributes are concerned you can also show all the attributes especially the primary so that you know that these are its major or identifying attributes so that your diagram is more simple and easier to understand so in today's lecture we have discussed our analysis phase and we will conclude this in our next lecture when we will draw this diagram in bits and pieces and finally we will see that our example system and its design and then we will take this design in our next lecture and ultimately implement it till the next lecture Allah Hafiz