1.1 DBMS In Hindi (Complete Playlist) - 8.15 View Serializability in DBMS

Namashkar, Dostu, Mahu, Abhkad, Dostu Sanjit and Swagat I am in this video series where we are discussing on DBMS So, in the last video we have explained many numerical try and conflict on the facility So, this video starts with discussion about the view facility First we will explain in this video what is the basic concept how the view facility identifies what approach and then we will continue discussing on that So, let us start with discussion the topic is the view serializability now view facility or any schedule view serializable is not there before finding this I have to discuss it is very important that actually the concept view facility is a problem if we try to prove any schedule what is the meaning of the problem because many people try to go through numerical or problems but its theory is very important because view serializability actually moral is a theoretical problem practically there is no use in practical use before discussing this topic let me explain that view serializability on that my knowledge is in the last 25 years I have never seen a numerical question on the internet if you have ever asked then one of the theoretical questions is because conceptually it is very tough to identify that any schedule view serializable is not there but of course university exam is very important in theory it is very important so, discussion is very important so, what is the idea? as you can see I have made a big rectangle which we have understood all the schedules this rectangle is a total number of schedules universal set of the main schedules you can see that schedule is two types either consistent or inconsistent we also think that what is the meaning of consistent if schedule means many transactions that we are currently running if we run them then our system is consistent or the guarantee of consistency then we know that schedule is consistent or the schedule is inconsistent now, let me see what we have discussed the idea is we have made a schedule so, we should identify whether schedule is consistent or not practically, it is very difficult because consistency is a definite definition that if I run all the transactions or I run them parallel to schedule then both the cases are the same then I will know that schedule is consistent but if you do it practically, it is not possible if you have done it then you have to do it so, we have understood this topic a type which we call conflict serializable schedule we have discussed the concept of the schedule then I will explain it to you we can divide the schedule by two types serial and non-serial and if there is a serial then of course, it is consistent then, the conflict serializability is a couple of things which is the idea that we do not know about the problem of non-conflicting instructions and convert it in serial and we know that because the serial is consistent then we prove that that non-serial schedule is also consistent this idea is the conflict serializability but see, you are understanding and clear the second thing that if there is a schedule if there is a schedule then what is consistent there is no doubt about that who is the conflict serializable but if there is a schedule then what is inconsistent then what is inconsistent then what is inconsistent and the first thing is because you will understand if there is a schedule that is not configurable then it can be consistent it can be inconsistent we do not know because it is not consistent it can be consistent then what is the meaning of this? this is good that the conflict serializability is a very usable approach and to solve this, there is a lot of difficulty like we had explained in the last video order of n square you can solve it in the cost of this but the question is that the child who is a consistent schedule is there any way to identify that child who is a consistent schedule then see, here, one thing we cannot find the consistent schedule now see here, the concept is that whose view serializability so view serializability is I will identify the graph view serializability is a weaker form of conflict serializability if you come from a conflict serializability then you come from a different view serializability area that means you will understand some schedule is possible but you cannot be a conflict serializable you will understand it in a area if you are a conflict serializable then you may be able to use the view serializable that is conflict serializability means let me say Canter Place in Delhi, view serializability is Delhi and knowledge of Consistences is India if you are in Canter Place then you are in Delhi but if you are in Delhi then you are in the Canter Place then you do not need this idea we will do the discussion we will do the view serializability the concept of the idea of the conflict serializability is also a consistent schedule can we not be able to catch one time we will clear it again what is it it can be a schedule is not conflict serializable or view serializable and then it is consistent that is possible all the consistent schedule we cannot identify we cannot agree but yes a little liberal form is a conflict serializability now see what is the approach if a schedule is a little bit more cover then logically what we should do because of the view serializability because of the more space but why not because algorithm will also understand that if a schedule is a view serializable or not is a NP-complete problem NP-C problem that is very complex you should know the problem in decidable problems or algorithm problems so until we are possible we should have a safe view serializability try to concentrate on all the things now what is the correct idea of view we will explain it from the numerical as I am saying view serializability is logically it is more cover and it is very difficult to find so until we are possible you will set the numerical in your study till we are possible we should have a safe view now take a look a schedule is written tell us if it is a view serializable now see this area we understand if a schedule is a conflict then it will be a view serializable because if you are in a place in a conflict then you are in Delhi if you have a question if you are finding a schedule then what are you finding in a conflict because most of the time if exam is set in exam then it can be a conflict but if it is a conflict then it will be a conflict and if your life is a conflict then it will be a view serializable and you need not reach the possibility of view serializability examiner is just checking whether it is a conceptually is it a topic of clarity or is it a conflict that view serializability is more concentrated and is a more restrictive form if a schedule is not a conflict then it is a shortcut that many people do not know that a condition is that if a schedule is not a conflict and that view serializable then it should be a blind right at least one of the points should be a blind right at least one of the points should be a blind right if a schedule is not a conflict and that view is a blind right now remember previous videos where we have explained what is the blind right if you write a value in a read then you will see that it is a blind right i.e. if i write a read and if i write a read then it is not a problem if you write a read or write a value in a read then it is a blind right now let me tell you what is a shortcut if a schedule is not a conflict and if a view is a blind right then what is the benefit of this first of all we will find a conflict if a conflict is a conflict then the view serializable is a problem if a conflict is not a problem then what will be the blind right and your benefit is because we know to be a blind right it is necessary if a blind right is not a problem then it means that the view is a blind and it is not necessary to check next time the discussion will only begin when a conflict is not a problem if a conflict is a problem then it is a view if a conflict is not a problem then we need to find a blind right because a blind right is necessary and this is the condition why is it so?

we will understand if a conflict is not a problem then you will not find a blind right or not a view now let me tell you this question மانلی جے کوئی شدیول جہے وہ کنفлекс لازبل نہیں ہے اور اس کنندر بلینڈ ریٹ ہے تو اب اس نے vue ڈلازبل ہونی کی جو میریمام کنڈیشانتی وہ پوری کر لی but اس کم ارے میں نے کہ vue ڈلازبل ہو جہے گا تو کہایٹے سمجھے گا اگر کوئی شدیول مانلی جہاں نے چک کیا کنفлекс لازبل اگر yes یا پھر νوں اگر نہیں اگر ہے تو vue ڈلازبل vue ڈا میں پک کا بتا ہے اگر وہ کنفлекс لازبل نہیں دوستو ہم دیکھنے ہیں bline right اگر bline right ہے تو ہم جا گے آگے چک کریں گے اگر bline right نہیں ہے تو پھر وہ vue ڈلازبل نہیں ہے یا میں پک کا پہلے سے پتا ہے اب چک کیسے کرنا ہے یا چک کرنا پہلے یہ دیکھے سبسل نہیں ہے تو اگر conflict ڈلازبل نہیں اور bline right ہے اس کامتل بھی نہیں کہ vue ڈلازبل ہے چک کرنے کے بعد پتا لگے گے وہ ہو بھی سکتا اور نہیں بھی ہو سکتا تو چک کرنے کا کنفر دیکھنے پھر سا مشکل ہے جس کی مالا جگلی بات کروں گا اگلی video میں لیکن یہاں دیکھیں پلے سمجھانا ضروری تھا کہ بیسک کنفٹ ہے کیا اور vue ڈلازبل نہیں ہے پوڑے سستم میں کہاں پے آتا ہے ہے نا تو دیکھیں اگلی video میں بات کریں گے کہ vue ڈلازبل نہیں ہے vue ڈلازبل نہیں ہے تو چک کرنے کیاں پر آتا ہے اور نمریقلی سمجھیں گے یہ بات کرنے کیاں مشکل کیوں ہے تو بیسک آئیریہ تو ہوں vue ڈلازبل نہیں ہے یہ شاٹ کرتا پر اچھا پر اچھا پر اچھا پر اچھا پر اچھا پر اچھا ہوں گی ہوں گی مجھ آپ اچھا پر اچھا پر اچھا پر اچھا اور اگلی video میں آپ کو بہتی سرل اور آسان شفضم آپ کو سمجھا دا ہوں کہ کیاں سے اگر یہ دونوں کے سو بھی جائیں تو آپ ایڈنٹی فائی کر سکنے کوئی شدیول vue ڈلازبل ہے کہ نہیں ہے تو پتک کے لیمجھے دیگھتھا سمجھا اور بہت جلدی آزرو توگلی video کے ساک تو پتکلے تو سو دھنے بعد