Clustered vs. Nonclustered Index Structures in SQL Server

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  • Опубліковано 26 лис 2024

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  • @nonam72
    @nonam72 2 роки тому +56

    No nonsense talk or waste of time.
    Straight to the point with excellent presentation examples.
    Good Work. Thank you very much.

  • @abhiramm4941
    @abhiramm4941 2 роки тому +41

    It is hard to believe that this video is from 8 years ago. Still the best video explaining the basics of both these indexes even in 2022.

    • @ColonelStraker
      @ColonelStraker Рік тому

      Is it just me or did his eyebrows grow, during the course of this video and its edits?

  • @falxonPSN
    @falxonPSN 2 роки тому +35

    This is one of the best videos on this topic out there. Keeps it simple, but still clearly explains the structures and how it works. Very nice work, sir!

  • @Alstash
    @Alstash Рік тому +3

    Elegant explanations like this are truly timeless, shifted through a bunch of videos attempting to word this same information in, like, double the time, and yet STILL failed to deliver as well as you did, sir, truly thank you.

  • @lorraineliu8422
    @lorraineliu8422 6 років тому +15

    I've watched over 10 video. This is by far the most clear structured introduction to indexes! Thank you!

  • @sharaf515
    @sharaf515 8 років тому +393

    Never before did Nicolas cage explain something so well, good job Nic.
    joking :D it was so helpful. thanks.

  • @xphon12
    @xphon12 4 роки тому +20

    Great explanation! This is the type of explanation that every developer can understand, no matter their programming level

  • @CorbinBohne
    @CorbinBohne 5 років тому +2

    I always come back to this video when I need a refresher and it never fails to help me. Thanks again!

  • @edwardsun4079
    @edwardsun4079 9 років тому +16

    Man, you fully rocked on demonstration the difference between Clustered Index and non-clustered Index ! This helps me on preparing for the interview questions !

  • @kzev
    @kzev 10 років тому +1

    You are awesome. Without ppl like you I would not have been able to build my skill at this level and get the job I now have. It all goes far. Thank you very much!

  • @davewhelton4166
    @davewhelton4166 4 місяці тому

    For 10 years, I've learned the definitions of both coz i just couldnt grasp what it actually meant but the 2nd time watching this video, you have finally made me understand

  • @nkproductions742
    @nkproductions742 5 років тому

    Incredibly beautiful explanation of clustered and non-clustered indexes. There is a lot of material in those first 6 minutes, and I admit I had to pause several times to absorb it and move, but hey who is complaining when you get there eventually.

  • @georgesmith9178
    @georgesmith9178 8 років тому +1

    I liked the visualizations best. The phrase "a picture is worth a thousand words" definitely applies to this video.
    Thanks for the concise and well delivered video. And, please, ignore the "Nicolas Cage" references below.

  • @radekou
    @radekou 9 років тому +61

    Wow, great explanation, love the usage of visualization of the data stored in structures. I've had an idea about how indexes work, but after watching this I'd be able to explain it to my grandmother (:

  • @reinersitanggang
    @reinersitanggang 8 років тому +2

    A lot wannabe blogs explained it with much much worse example, even a lot that even do not define from the scanning process through accumulate the results. Nice vid!

  • @indric
    @indric 10 років тому

    I understood more from this video than from a whole semester of lectures. Thanks!

    • @VoluntaryDBA
      @VoluntaryDBA  10 років тому

      You're very welcome! I'm glad it helped you understand these concepts.

  • @amaxamon
    @amaxamon 4 роки тому

    I know this has been up for 6 years but THANK YOU!!!!

  • @tehawes0mesauce
    @tehawes0mesauce 8 років тому +1

    This video might save my advanced databases test grade tomorrow. I hate when the prof. doesn't explain stuff clearly enough for me. Thanks for the video - liked and subbed! :)

  • @kezhan01
    @kezhan01 8 років тому +1

    Wow, I could not image a man can explain it in such a simple way! Thank you!

  • @TheLastSamurai74
    @TheLastSamurai74 10 років тому +5

    the best tutorial i have ever seen for MS SQL indexes, good job my friend

    • @VoluntaryDBA
      @VoluntaryDBA  10 років тому

      Thank you very much! I'm glad it helped you.

  • @michaelgebreselassie99
    @michaelgebreselassie99 8 років тому +1

    I have been looking for different sources just to objectively understand the difference between clustered and non-clustered indexes and to know how they really work. This very short and precise video have put an end to all of my Qs. Thank you.

  • @mehdizeynalov1062
    @mehdizeynalov1062 2 роки тому

    This man knows what he talks about - great. Waiting other videos.

  • @samlinus836
    @samlinus836 2 місяці тому

    Man, you've researched a lot such a quality video, you just kept answering all of the questions that I had referencing blogs and videos. God bless you brother

  • @imrana.8370
    @imrana.8370 9 місяців тому

    I had a hard time understanding the difference until I watched your video. Thanks for the simple explanation!

  • @camelCased
    @camelCased 9 років тому +1

    Thanks for the video, the phonebook example was good and easy to understand.
    From my experience, things sometimes get confusing because of different default behavior of different RDBMS - some automatically create clustered indexes for primary keys, some automatically create indexes on foreign keys, and some don't do any of this. So, sometimes you might get unpleasant surprises and performance issues if you have to deal with a RDBMS which you don't have experience with.

  • @manasr3969
    @manasr3969 11 місяців тому

    Excellent video. Much easier with visuals than reading articles. Keep up the good work.

  • @akashverma1640
    @akashverma1640 Рік тому

    This is all I was looking for. Best explanation about behind the scenes of indexing.

  • @danm2756
    @danm2756 8 років тому +3

    wow....best explanation. I'm studying for the mcsa exam. I've been struggling with this topic. thanks!!

  • @ArtemMikhaylov
    @ArtemMikhaylov 8 років тому +8

    Perfect explanation I've ever seen before! Please do not stop!

  • @troop53no
    @troop53no 6 місяців тому

    Thank you! I interact with a SQL database often, but indexes are not something I deal with enough. This was great information and exactly what I needed (:

  • @Akshay-Raut
    @Akshay-Raut 8 років тому +1

    its simple to understand with graphical representation. Keep up with them. Great work.

  • @Devilfairy1
    @Devilfairy1 7 років тому

    Best indexing explanation I've seen on internet.

  • @Major_Mason
    @Major_Mason 5 років тому

    I am just starting to learn SQL. My dad is going to give me lessons, but this certainly helped me understand some of the terminology. I figured since I am already a Network Engineer who is two months away from his bachelor's degree, I want to make myself more valuable.

  • @tommccann3559
    @tommccann3559 10 років тому +1

    Bravo! That is most succinct explanation of clustered indexes I have ever read or seen. I've got it now :-)

  • @ommi3756
    @ommi3756 10 років тому +1

    Never get this clear until this video. Nice!

  • @TijiMathewrjj
    @TijiMathewrjj 7 років тому +2

    Very well illustrated and explained thoroughly. Well done.

  • @jaquesaulait
    @jaquesaulait 7 років тому

    Nice, clear delivery, good explanation. And he said "zed"! He speaks proper English..!

  • @serhankars
    @serhankars 10 років тому +1

    One of the best tutorials I've ever seen. Thank you so much. Brief and infomative. Animations are very helpful also.

  • @jonobaker
    @jonobaker 7 років тому +3

    This video helped me ALOT, I've been watching many videos and this really clearly cleaned things up for me. The moving graphics were a big part of that too.
    thankyou!

  • @akankshakaul744
    @akankshakaul744 Рік тому

    Excellent video. Finally I could find a video which is so crisp and clear. Thanks a ton!!

  • @pradeepdesai9952
    @pradeepdesai9952 9 років тому +2

    Nicely put.. Specially graphical visual are the one which makes one understand much better .. .Thank you so much ...

  • @CorbinBohne
    @CorbinBohne 8 років тому +1

    This is a fantastic explanation that a lowly analyst like me can understand :)

  • @ladhkay
    @ladhkay 4 роки тому +1

    Most concise and easy to understand video out there. Thx man!

  • @ezequiel_code
    @ezequiel_code 7 років тому +1

    it can't be better explained, excelent work

  • @roidelalune01
    @roidelalune01 10 років тому +1

    Very consistent video. I hope you will add more on this topic. thank you very much

  • @sathwicksv
    @sathwicksv 4 роки тому

    Thank you very much, I have been reading at many places but no one explained with images. Greate video. Even MSDN documentation doesn't have this much information.

  • @vincewon8591
    @vincewon8591 7 років тому +2

    Thank you so much for posting this! I was having a hard time understanding the differences between the two until i watched the video.

  • @TheGothicSecret
    @TheGothicSecret 10 років тому +1

    Thank you for painting and diving deep in details of indexes!

  • @AC-ft6mx
    @AC-ft6mx 4 роки тому

    Never it was explained so well by others. Thank you !!!

  • @jacksrensen4475
    @jacksrensen4475 2 роки тому +1

    Very good explanation ;) My tutors have tried to explain clustering and indexing for me multiple times, without my understanding. But your examples and explanation of the differences really helped

  • @RAZR_Channel
    @RAZR_Channel 3 роки тому

    This video is well explained... I don't understand 148 dislikes... if he's talking about things you don't understand: then you need to go to lower level explanations... and then come back here.

  • @srapdy6960
    @srapdy6960 7 років тому +1

    Excellent explanation. I don't think this can be described any better. Great visuals. Thank you so much

  • @paoloberg70
    @paoloberg70 4 роки тому +2

    This is very clear, finally someone who explained in a clear simple and efficient way the index. thanks again!

  • @marcchen4574
    @marcchen4574 9 років тому +3

    I went through many other tutorials, this one really stands out

  • @mike_yon
    @mike_yon 6 років тому +4

    This has been a great straightforward video that really helped explain the difference. Thank you keep up the good work!

  • @iainelder7607
    @iainelder7607 11 років тому

    Thanks, Jon. I liked the visual example of the phone book - helped me to understand how indexes work without getting bogged down in bytes and pointers.

    • @VoluntaryDBA
      @VoluntaryDBA  11 років тому

      You're very welcome! That's exactly what I was going for.

  • @ashish7459
    @ashish7459 9 років тому +6

    Really amazing, I was not aware that we can define type of index while applying primary key or unique constraints. thanks for amazing explanation :)

  • @samlinus836
    @samlinus836 2 місяці тому

    I would love to see more videos on Ambiguous concepts of SQL on this channel thanks man.

  • @TheJimboNJ
    @TheJimboNJ 6 років тому +1

    Thank you!! I particularly liked your examples and your methodical delivery of the information. I found the examples to be very helpful as well!

  • @js34lee
    @js34lee 7 років тому

    you have saved my life !!!!! genius explanation. I have been struggling to understand this for months after months

  • @ckeveny1
    @ckeveny1 10 років тому +1

    This is very useful. I now understand non-clustered indexes. Thank you

  • @condemned8916
    @condemned8916 7 років тому +1

    Sir 5/5 for this video , the visualization was a gr8 help in understanding . I had some knowledge that B-tree was the index data structure but could not grasp it , but after your video it helped me a lot. Plz do post more such videos.

  • @ПавелЧижиков-ю4ф
    @ПавелЧижиков-ю4ф 3 роки тому

    Awesome video. Amazing how easy this guy explains such tricky material. Brilliant! :)

  • @gauravbabbar9808
    @gauravbabbar9808 6 років тому

    Best explanation i have seen for this topic. Thumbs up man.

  • @glebski1531
    @glebski1531 9 років тому +3

    really awesome explanation of a concept that I come across every day that has perplexed me to date... thank you sir !

  • @ssaraswatipura
    @ssaraswatipura 9 років тому +1

    Awesome presentation, looking forward to watching more of your presentation.

  • @Yousafkhan-gv7cs
    @Yousafkhan-gv7cs 10 років тому +1

    Very helpful especially the way you explain and display the concept.

  • @sasanfakharpour7175
    @sasanfakharpour7175 10 років тому

    Thank you for a great video. But a Heap table is defined as a table without a Clustered Index and not just an index. Nonetheless, a great explanation.

    • @VoluntaryDBA
      @VoluntaryDBA  10 років тому

      You're welcome! I can't re-watch the video right now to see if I misspoke, but yes, you're correct, a heap is a table with no *clustered* index.

  • @atiqulny
    @atiqulny 10 років тому +1

    Excellent clip. I'm new the SQL Server and this information is very informative.

    • @VoluntaryDBA
      @VoluntaryDBA  10 років тому

      You're welcome! I'm glad it helped you.

  • @programmingbeasts4649
    @programmingbeasts4649 5 років тому

    The best explanation of the indexes in SQL thank you so much

  • @rohitdubey9929
    @rohitdubey9929 2 роки тому +1

    very useful .. why you stopped making video ?

  • @mvmassoudi
    @mvmassoudi 10 років тому +1

    Very Professional, clear and informative; I also loved the video animations. Thank you

  • @Njoiraja
    @Njoiraja 4 роки тому

    Nailed it. You earned a Subscription from a fellow DBA!

  • @Watch-N-reWatch
    @Watch-N-reWatch 10 років тому

    Thanks Voluntary.. This video was awesome.. I have been a years in Database but its first time I came to know what index is all about.. Thanks for your great example and way presentation.. U guys ROCK!

  • @dominicinzerillo7055
    @dominicinzerillo7055 10 років тому +1

    Great stuff, made so much more sense then the books i have read.

    • @VoluntaryDBA
      @VoluntaryDBA  10 років тому

      All it takes is one "ah-ha!" moment, no matter where it comes from. :) Thanks for watching!

  • @mikedaniels755
    @mikedaniels755 5 років тому

    Perfectly concise and to the point. Well articulated and the visualizations help dramatically. Thank you very much for your contribution to the DATA world :)

  • @naveenkumar7262
    @naveenkumar7262 10 років тому +1

    Thanks for this nice video. It was short, simple and easy to understand.
    Thanks again!!

    • @VoluntaryDBA
      @VoluntaryDBA  10 років тому

      You're very welcome! Thanks for watching.

  • @pradeepn6328
    @pradeepn6328 7 років тому +1

    Nice Video, The way he explaining is extraordinary

  • @Jemmeh
    @Jemmeh 9 років тому +1

    Great video, very well put together and simplifies the topic well.

  • @viveksingh100k
    @viveksingh100k 8 років тому +1

    Explained in very short time .. Thanks very much :)

  • @kamalbalasubramanian621
    @kamalbalasubramanian621 6 років тому

    Best explanation with visuals. Kudos!!

  • @pablocazares4521
    @pablocazares4521 8 років тому +1

    very good! much better then others I've watched

  • @MegaMajboor
    @MegaMajboor 10 років тому +1

    A great and understandable explanation! An outstanding video. Plz keep it up. Thanx sooooo much

    • @VoluntaryDBA
      @VoluntaryDBA  10 років тому

      Thank you very much, and you're welcome!

  • @NatashaSalam
    @NatashaSalam 9 років тому +1

    Great video, thank you for creating this and explaining the concepts in a concise and visual manner.

  • @mohsenhs
    @mohsenhs 7 років тому +1

    Awesome tutorial, Visualised and explained well, Fantastic, Many thanks

  • @Vlfkfnejisjejrjtjrie
    @Vlfkfnejisjejrjtjrie 7 років тому +2

    great visual representation and model choice. subscribed!

  • @williamchin-fook8097
    @williamchin-fook8097 7 років тому +1

    Great Explanation and analogy about clustered-indexes 5 star!

  • @RucuryBeans
    @RucuryBeans 7 років тому +1

    Very useful, thanks for making the video and explaining the concepts so well!

  • @michaelkennedy5126
    @michaelkennedy5126 11 місяців тому

    Thanks friend, that was a clear and concise explanation with excellent graphics.

  • @maitri3
    @maitri3 10 років тому

    YOU are the my hero today. I love your slow and clear explanations. Mil besos.

    • @VoluntaryDBA
      @VoluntaryDBA  10 років тому

      You're welcome! I'm glad this video helped you.

  • @nareshnama343
    @nareshnama343 7 років тому

    Thank you ...very help full and wonderful demo..we are expecting to see more demos off SQL server from you..

  • @rajeshpednekar9317
    @rajeshpednekar9317 5 років тому

    Nice Simple explaination on Clustered Indexes and Non Clustered ..

  • @pedropinto2192
    @pedropinto2192 5 років тому

    Very useful video! Your visual graphics made it very simple to understand. Thanks :)

  • @khaleda4873
    @khaleda4873 4 роки тому

    You are so chill bro, thanks for the video.

  • @AlexJordan-d9l
    @AlexJordan-d9l Рік тому

    Buena explicacion, estoy dando mis primeros pasos en SQL server, y tu explicación me aclaro muchas dudas

  • @GhOnAu
    @GhOnAu Рік тому

    Great work, learned quite a lot about such a important topics in database the slides and visual explanation was piece of master piece

  • @pjkumar5016
    @pjkumar5016 10 місяців тому

    This is awesome, I referred lost video but this one really hits me. This is next level explanantion.

  • @Quatrei45
    @Quatrei45 10 років тому +1

    Thank you, love the video.
    Thanks, but I have a question, say for example your non clustered index is attached to the first name and last name and you included the phone number, how will the scanning of records go through these queries
    SELECT * FROM Table
    WHERE FirstName='Jhon'
    OR PhoneNumber='1234567'
    since the PhoneNumber is dependent on the ordering of the FirstName and LastName, does that mean it will still do a table scan or worse?
    also with the scenario
    SELECT * FROM Table
    FirstName LIKE '%a%'
    since the names of the left and right nodes can have 'a' in their names, will this also be a table scan or worse?
    Thanks in advance!

    • @VoluntaryDBA
      @VoluntaryDBA  10 років тому

      Quatre43 Hi, thanks for the questions.For the first example, assuming there are no other indexes and the table is a heap, it would result in a
      scan of either the NC index or the base table. The OR precludes the exploitation
      of any ordering because a single index cannot satisfy both of the =
      predicates with seeks (it can satisfy one or the other, but not both). Adding a second index with a key that leads with PhoneNumber may result in a more efficient seek-based plan depending on the selectivity of the = predicates.For the second example, this must scan because of the leftmost %, which means FirstName can start with any character -- therefore there's no way to exploit the index key order with a seek. As far as I'm aware right now, there's no *easy* way to make this query more efficient.Let me know if you need more clarification.

    • @VoluntaryDBA
      @VoluntaryDBA  10 років тому

      Sorry for the formatting, newlines in comment replies has been broken for some time now.

    • @Quatrei45
      @Quatrei45 10 років тому

      Voluntary DBA Thanks man, i also tried it earlier and got a better understanding of execution plans. thanks :)

    • @VoluntaryDBA
      @VoluntaryDBA  10 років тому

      Quatre43 You're welcome. Glad I could help.

  • @rhadooh
    @rhadooh 4 роки тому

    Bravo! A very good explanation, but it would help a lot to specify when the subject changes: for example when we switch to FILTERED INDEXES and then to INDEXES WITH INCLUDES COLUMNS...
    But then again, thanks a lot, a very good explanation!!!

  • @kirkin2006
    @kirkin2006 8 років тому +2

    Very clarifying video. Many thanks sir. I lost a job oportunity because not knowing the difference between Primary key and Unique key... :(

    • @VoluntaryDBA
      @VoluntaryDBA  8 років тому +1

      I'm sorry to hear that, but I'm glad you learned something from the video to prepare you for next time.