I did multiple certifications on SQL from reputed online learning platforms and even bought advance SQL courses on Udemy but even they do not teach these things. Hats off to you, it's because of your videos I go super confident in my interviews now.
Sir, please make video on INCLUDE(columns) along with non clustered index and why we don ot use it on clustered index. That is very important operation while optimizing query cuz large description(nvarchar(max)) colums slows down non clustered indexes too when they are in the select
Excellent explanation of these key concepts of sql server indexes and analyzing query execution plans. I am looking for more videos about other query plans such as nested lookups.
when we don't provide a clustered index. RID lookup happens because the engine by default creates a RID for all rows and stores them by increasing order of RID. But if we have clustered index on Id, then data is already stored in increasing order of id. Now key lookup happens. Key point is that, lookup has to happen on ordered data. RID/KEY fulfills the same purpose.
Hi Kudvenkat, I wonder if this series will be continued? or if the continued series is moved to other platform because I found your tutorial is very easy to understand and very helpful. Will looking for buy a online course regarding this topic if you're going to publish one
Hi Kudvenkat, I've been waiting for your series on SQL Server performance tuning for a long time. And you are doing awesome work on this. Please try to make this series for each physical operator of the execution plan and explain the reason behind them and what changes on SQL queries can avoid these heavy operators.
You are an awe-inspiring🤗 Can you teach us how to analyze a system and convert requirements to ERD 🌟 or anyone recommend me any source to understand this topic well.
So the RID is kind of like a primary key which is internally created by sql server for indexing purposes only as there is no primary key given by the user in the table, Right?.
@@Csharp-video-tutorialsBlogspot if you could do some videos explaining about what is table partitioning and how it is done, that would be really helpful.
Hi Venkat, thanks for the great content! Can I clarify with you, if there's no clustered index key, how does SQL do a row ID look up? Since the heap is not sorted in any particular order, when doing a row ID look up, does it imply a full table scan?
I have question: if we only use nonclustered-index , then data is not sorted in the leaf node, then we use RID to look up , do we have to go to each page to know which data row in which page is equal to the RID that we use in the index tree ?
Hello Sir, Thank you for the detailed explanation. Quick query, please? The non-clustered index has been created based on the "Name" column only. How is the RowId column been stored in the index as a key-value pair, please? The RowId column is not even a column in the table. Also, this is table doesn't have a Primary Key column defined, then how does the RowId column has been stored in the non-clustered index, please? Could we expect more videos related to SQL Queries tuning, please?
This is very nice. Can you create a video with composite index? Like how the data is seek/scan when you have composite index on (col1, col2) but you’re only searching by col2.
Is it a good practice to include the pk value in the section INCLUDE of a nonclustered index? Sometimes we want to know which is the table’s id for a certain indexed column and to avoid a key lookup we could read it from the index itself, is it a good idea?
Hello Venkat, Nice videos you have in all your playlists. I have a little confusion though. Like you explained that data rows get stored in leaf nodes in Clustered index, where do actual data rows get stored in Non clustered index ? All I see are row locators on leaf nodes which I am guessing are row ID based on which RID lookups get created. Also need little elaboration on key values. Thanks.
Hi, Venkat I have registered for few courses on your website but none of courses have been started yet. I even dropped a mail regarding the same but no response from your end.
Hello YIC - Very sorry, there are just too many emails and did not get time to get to them yet. Sorry, did not mean to ignore. Thank you for understanding. Can you please share the course page URL here and I will be able to help. Hope you are finding our videos useful.