SCD: Slowly changing dimensions explained with real examples

[@TechCoach]

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[@andrewomofonma7148]

what about a situation where by the current snapshot doesn't contain the last data especially in a case like the employee is fired or left the job and that information is reported in a different table .How do you update the previous date and at that point will you maintain the current flag as 'Y' or'N'

[@himanshudhiman761]

SCD explained very well and with so much patience. !! Much appreciated... Thanks for sharing the knowledge on it

[@TechCoach]

Thanks for the kind words buddy :) Please consider subscribing to my other channel as well it will really help me kzbin.info/www/bejne/bHiUqXqfYqlopdk

[@kanojdebbarma6936]

Very well explained. I had an issue where I had implemented SCD 1. Later SCD 2 replaced it. I would say SCD 4 is a more elegant way. Great job! thanks for this video

[@mariejoycesantiago]

This is very informative, very easy to understand. Thank you so much for this!

[@TechCoach]

I am glad I could help :)

[@majidgolnar7415]

Hi Vivek, Thank you for this video. It helps me a lot. I have watched several training in SCD but they made me much more confuse. But this video helped me to understand. Just I want to mention that as far as I know the surrogate key should change in each update in SCD2.

[@TechCoach]

Thanks Majid, with every change ( insert in ScD 2 the surrogate key should increment)

[@anandbgrowthcoach]

Great video. Thanks a lot Vivek for explaining very simply and clearly!

[@TechCoach]

I am glad Anand I could help :)

[@atchutharaojami3109]

Excellent performance bro really very nice and clear explanation such containt all the best bro

[@TechCoach]

Thanks Buddy, please consider subscribing to my other channel it will really help me kzbin.info/www/bejne/nYXKZ6F5itqMhZo

[@sravanreddy8802]

Thanks a lot for this video. It really helped me understand SCD and its various types.

[@TechCoach]

I am glad I could help :)

[@praneethbhat6361]

good explanation . Really helpful for me. Tq

[@TechCoach]

I am glad I could help :)

[@ngowriraj]

Very Good with example & explanation

[@vishnuvardhanreddy5986]

Superb explanation understand very easily thank you so much bro......

[@TechCoach]

Thanks Buddy

[@Buzzingfact]

great explanation... thanks for the video

[@TechCoach]

Thanks a lot buddy, I am glad I could help :)

[@mandardegvekar997]

Simple and easy !! Great work

[@TechCoach]

Thanks a lot for the kind words Mandar :)

[@shukriabdulahi7492]

clear and practical examples. good job

[@TechCoach]

@shukri thanks for the kind words. Please consider subscribing to my other channel as well. It will really help me. kzbin.info/www/bejne/bHiUqXqfYqlopdk

[@mounikayathakula8585]

Hi..Thank you so much for this valuable information that helps me a lot

[@rajatnagwal7881]

amazing explaination.great job bro

[@TechCoach]

Thanks a lot buddy :)

[@w0nderw0manjy]

Awesome explanation.. totally worth it!

[@TechCoach]

Thanks Jyoti for the kind words. Please consider subscribing to my other channel as well. It will really help me. kzbin.info/www/bejne/bHiUqXqfYqlopdk

[@pinakeshchandradas7617]

Thanks dada (bhaiya) for your clear and concise approach to scd.

[@TechCoach]

Thanks buddy for the kind words. Please consider subscribing to my other channel as well kzbin.info/www/bejne/bHiUqXqfYqlopdk

[@job_updates_with_subham]

Very well explained with nice example 🙂 thanks

[@TechCoach]

Thanks a lot buddy :)

[@jyotikothari499]

Too good and simple explanation of SCD.. 👍🏻

[@shrutisinghal8556]

Superlike!! What I like about your videos is that you give real examples.

[@TechCoach]

Thanks a lot shruti :)

[@aliveniveluru9522]

very nice video, good knowledge sharing

[@TechCoach]

Thanks a lot for the kind words. I would really appreciate if you help me in my new Initiative "An Indian Abroad" by subscribing viewing and sharing. kzbin.info

[@KalyanS]

nice explanation with examples

[@templar273]

best explanation ever you are the best

[@TechCoach]

Thanks a lot Henri :)

[@MsMegha16]

very nicely explained. Thankyou

[@TechCoach]

Thanks a lot Megha

[@marchanselthomas]

Beautifully explained!

[@TechCoach]

I am glad I could help

[@golden9161]

Very crisp and to the point.

[@TechCoach]

Thanks buddy for the kind words, Please consider subscribing to my other channel as well, it will really help me :) kzbin.info/www/bejne/bHiUqXqfYqlopdk

[@TechCoach]

@golden, please consider subscribing to my new channel it will really help me kzbin.info/www/bejne/bHiUqXqfYqlopdk

[@arunasingh8617]

Amazing Video (y). Get going!

[@TechCoach]

Thanks a lot Aruna :)

[@uditech7736]

Simple and clear explanation. Thank you Tech Coach.

[@TechCoach]

Thanks Udi Tech for the kind words, I have a small request.I am working on this new channel and will really appreciate if you watch and subscribe to it kzbin.info/www/bejne/oGi1o6t7o7-Sbqc

[@susilkumarsahoo2532]

Nice once Vivek......Keep it up

[@vaibhavagrawal953]

Very precisely and beautifully explained. I was able to understand each and every thing you explained. 👏

[@monywa2007]

Hello Vivek ..thanks for sharing. I noticed that for SCD Type 3 example (at 14:50) when the salary value changes, you left out to put prev_salary and current_salary in the table although you did explain in your video that if there are more than one column change for each column there must be both previous and current values to be kept in DW.

[@ririraman7]

It was knowledge rain for me, thank you brother for the social work!

[@VinLopez]

well explained; this SCD types always ask during technical interview.

[@TechCoach]

Thanks Vin for the kind words I have a small request I am working on this new youtube channel, I Would love it if you watch and subscribe to it as well. kzbin.info/www/bejne/fZ-5n2ajhaeFsJY

[@gregorclegane7563]

Lol i was asked this in an inteview. I said I've never heard of it. After watching this video, it turns out that I've been working on SCD for severals years now. 😂😂 I just didn't know they were called as such.

[@vkd9442]

@@gregorclegane7563 exactly bro.. Just now I was asked this.. I said I don't know and searching in KZbin now. Found this

[@vijaykhanna7263]

Nicely explained.

[@TechCoach]

Thanks Vijay for the kind words :) please consider subscribing to my other channel as well.it will really help me kzbin.info/www/bejne/bHiUqXqfYqlopdk

[@vaibhavaher7139]

9:52 ID Column I assume as a Primary key in that case in Data warehouse table new ID gets generated or Same ID get repeated?

[@aishwaryavakhariya3999]

Thank you it is very helpful for me

[@TechCoach]

Thanks buddy, I am glad I could help :)

[@yashodhanjoshi781]

Thank you! Super concise and clear

[@TechCoach]

Thanks a lot buddy :)

[@kishanjadhav8944]

Very well explained . Thanks

[@hirenparikh1364]

Excellent Explanations Skills!!!

[@TechCoach]

Thanks Hiren for the wonderful comment. I have a small request I am working on this new youtube channel and will really appreciate if you watch and subscribe to it. kzbin.info/www/bejne/fnO0eZihgpaIaMU

[@vivekgambhire1379]

Really great video ,easy to understand

[@TechCoach]

@Vivek, Thanks for your kind words. It made my day :) Please consider subscribing to my other channel as well. It will really help me. kzbin.info/www/bejne/bHiUqXqfYqlopdk

[@nehabansal7609]

Best explanation ever

[@TechCoach]

Thanks Neha , Please consider subscribing to my other channel as well it will really help me :) kzbin.info/www/bejne/bHiUqXqfYqlopdk

[@nehabansal7609]

@@TechCoach done :)

[@tanushreenagar3116]

Nice sir 👌 👍 👏 😀 thanks 😊

[@TechCoach]

Thanks a lot Tanushree :)

[@sivanjaneyareddy]

The way of explanation is damn clear... Very useful for beginners. Thanks a ton for this video

[@TechCoach]

+Sivanjaneya Reddy M.V. Thanks a lot for the kind words :)

[@TechCoach]

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[@diptianjarlekar4480]

Very nice explanation and real life examples ..kudos

[@TechCoach]

Thanks Dipti for the kind words, I have a small request. I am working on this new youtube channel and will really appreciate if you watch and subscribe to it. kzbin.info/www/bejne/f4GVh6Fsn7Brfsk

[@4rmtinc]

Thanks. Nice and concise explanation of the different types of SCD.

[@TechCoach]

Thanks a lot for the kind words :)

[@TechCoach]

Thanks a lot for the kind words :)

[@Anilkumar-kp8ee]

Vivek brother it's awesome

[@TechCoach]

Thanks a lot for the kind words :)

[@vasupradhaswamy769]

thank you for such good video

[@TechCoach]

Thanks Vasupradha :)

[@nishanthkumar4743]

Well explained vivek... Big thumps up

[@TechCoach]

Thanks a lot for the kind words Nishanth :) This video may interest you as well . kzbin.info/www/bejne/a5_JeaCebbOmftk

[@chandu9143]

Nice explanation sir good 👌

[@TechCoach]

Thanks buddy for the kind words :)

[@ushasingu1757]

Very well explained. Thank you!

[@TechCoach]

Thanks Usha for the kind words. I have a small request I am working on this new channel "An Indian abroad" and will really appreciate if you watch and subscribe to it. kzbin.info/www/bejne/Z2KnfGClrrekopI

[@ParthSahakne]

Very nicely explained

[@TechCoach]

Thanks Parth for the kind words :)

[@Dinaklalthillankeri]

Very nice man❤️❤️

[@TechCoach]

Thanks buddy, please consider subscribing to my other channel as well. kzbin.info/www/bejne/bHiUqXqfYqlopdk

[@Adbhutashole]

Dear Sir , is primary or surrogate key in SCD2 will remain same for multiple entry of the same record ? As mentioned in this clip if it will remain same then how will we update the previous record ?

[@TechCoach]

Surrogate key will change, No two rows can have the same surrogate keys

[@chinnu2894]

If my source table has no date column, Can we apply SCD 2 on my source table to update?

[@TechCoach]

You can use the date when you recieve the row for the 1st as created date, whenever you recieve an update for that row you can use that as updated date. The only conern here is if the update to your olap system is not on a daily basis your created ( start) and updated (end) date may not show the perfect picture.

[@chinnu2894]

Thank you for clarification

[@baluhadoop4518]

thats awesome...very well explained..thank you very much bro.

[@TechCoach]

Thanks buddy for the kind words, this video on indexing may interest you as well. kzbin.info/www/bejne/Zomck5WqrLmhq6c

[@raviranjansingh5527]

Great explaining sir ,make more update video sir

[@TechCoach]

Thanks Ravi for the kind words, sure I willwork on them

[@ahmadsyed9405]

excellent stuffs and nicely explained.

[@TechCoach]

Thanks Ahmad Syed for the kind words. I have a small request, I am working on this new channel please do watch and subscribe to it. Your support is my motivation. kzbin.info/www/bejne/gKDFgIGfi7x0b7M

[@pranavbhat92]

Thank you for the clear explanation!

[@TechCoach]

Thanks Pranav for the kind words, This video on Indexing may interest you as well. kzbin.info/www/bejne/Zomck5WqrLmhq6c

[@NeuraKnowledgeTV]

Well explained

[@TechCoach]

I am glad I could help

[@sikandarbaig2125]

thank you so much very help full

[@TechCoach]

I am glad I coulf help :)

[@sreejithsreedhar05]

You deserve much more viewers than now since you narrated the concepts very well,I like your videos, Thanks, dear friend.

[@TechCoach]

Thanks a lot sreejith for the kind words, you made my day. I have around 80 videos and your comments boosted my confidence to make many videos. Thanks a lot again.

[@rahulsalve7543]

Very nice video...just remove subtitles for better understanding...due to that we can not see the tables

[@TechCoach]

Sure Rahul, Thanks for the inputs :)

[@spankyx8606]

thanks for the excellent lesson and clear sound

[@sanjayMishra-vs9um]

Thank you very much for this simplest explanation I could find over youtube! Awesome :)

[@TechCoach]

Thanks Sanjay for the kind words :)

[@Ravikumar-bu7ge]

Very well explained. Thanks a lot..

[@AnIndianAbroadd]

Thanks a lot Ravi for the kind words. I have a small request, I am working on this new channel and will really appreciate if you watch and subscribe to it. kzbin.info/www/bejne/Z2KnfGClrrekopI

[@melvin9993]

Good Job!

[@TechCoach]

Thanks buddy

[@they_callme_kkc6812]

Thank you so much bhai 💙

[@TechCoach]

Thanks buddy :)

[@agastya4700]

sir, dwh is non volatile ,but in scd 1 and 3 it will over write . how it is possible to alter the dwh?

[@TechCoach]

SCD concepts are same for all kinds of DB , SCD 1 is quite popular in ODS .

[@agastya4700]

sir as u told ,in scd 1 data will be overwritten in datawarehouse . but data ware house is non volatile ,then how in scd 1 ,data overwritten?

[@agastya4700]

​@@TechCoach sir, i think you didnt get my question ? can I change or manipulate data in dataware house?

[@TechCoach]

@@agastya4700 In datawarehouse ideally we maintain historical versions of our dimension data so you won't see SCD 1 implementation in general. But there may be situations where maintaining history of certain dimensions mayn't make much sense so you may see the latest versions there. Also organization may dispose off data older than certain years to ensure compliance and performance.

[@lemmiTry]

Very informative and concise video. Thanks!

[@TechCoach]

Thanks for the kind words.I have a small request, I am working on a new channel " An Indian Abroad" and it will really help me if you watch and subscribe to it. kzbin.info/www/bejne/Z2KnfGClrrekopI

[@mohammadjamshaidsayeed6564]

Thanks, Vivek, really its very good video to understand SCD. If you have any video with the practice session plz share a link for the same which helps more clear.

[@TechCoach]

Thanks Mohammad , Unfortunately at this moment i don't have a practice video on it.

[@mohanrajmech89]

This is some wonderful explanation. And they way you explain is so easy to understand and follow. Thank you so much Bro!

[@TechCoach]

Thanks Mohanraj for the lovely words, I am glad I could help :)

[@9704004030]

Can you do a video on Change data capture...

[@TechCoach]

Sure buddy I will work on it :)

[@aamirirfan8768]

Once again Good work Vivek

[@TechCoach]

Thanks a lot for the kind words. I would really appreciate if you help me in my new Initiative "An Indian Abroad" by subscribing viewing and sharing. kzbin.info

[@MitziMuzic]

Too good 👍👍

[@TechCoach]

Thanks buddy :)

[@bhaskerreddyvade]

It’s pretty cool thank you

[@TechCoach]

Thanks Bhaskar for the kind words :) Please consider subscribing to my other channel as well. It will really help me. kzbin.info/www/bejne/bHiUqXqfYqlopdk

[@bhaskerreddyvade]

I shared to few members

[@shubhamchouhan8149]

please upload videos regarding SCD based scenarios wth both SQL and informatica (two approaches) your explanation methodology is very good.

[@TechCoach]

shubham chouhan Sure Shubham I will work on it soon

[@sasidharsamala1889]

Simply awesome

[@keithdoran728]

Thanks for the clear explanation

[@TechCoach]

You are welcome Keith :)

[@jahangirkabir9271]

great simple explanation!!

[@TechCoach]

Thanks a lot for the kind words :)

[@TechCoach]

I would love your support for my new channel, Please watch subscribe and share with your friends. kzbin.info/door/oLdaMxhfDgdgIAcRGlUvkg

[@puttamadhukarreddy]

Awesome bro...keep doing 👍🏼

[@AnIndianAbroadd]

Thanks a lot for the kind words, I have a small request I am working on this new youtube channel " An Indian Abroad " and will really appreciate if you watch and subscribe to it. kzbin.info/www/bejne/Z2KnfGClrrekopI

[@AliRaza-nl6tf]

Informative.

[@TechCoach]

Thanks buddy for the kind words :)

[@mullaipugazhendi3236]

Excellent 😊

[@KalyanS]

Nice explanation

[@jaivalsartandmore....1199]

Much appreciated ....

[@TechCoach]

I am glad I could help

[@JessicaRocha-dz4cw]

Thank you so much for you explanation, it was very clear!

[@TechCoach]

Thanks a lot for the kind words, I have a small request I am working on this new youtube channel " An Indian Abroad " and will really appreciate if you watch and subscribe to it. kzbin.info/www/bejne/Z2KnfGClrrekopI

[@piraviperumal2544]

Good one!

[@TechCoach]

Thanks a lot buddy for the kind words :)

[@sujaa1000]

Thank you Vivek! this was very helpful. Regards, Sujaa

[@TechCoach]

Thanks Sujaa for your constant feedback, It helps me going :)

[@jhansikuncham477]

Hi Bro can you please do videos on Informatica PowerCenter

[@TechCoach]

Sure buddy :)

[@aishpizza]

Can you please say why there is not SCD 5 ?

[@TechCoach]

SCD5 wasn't available when I created this video

[@RealLifeAnnu]

Good info

[@ladysay3]

Thanks. Great video.

[@TechCoach]

Thanks buddy for the kind words :)

[@sujalpadhiyar5731]

Question: In SCD3 why columns are created for only location, When it comes to change in dimensions for salary & date , why there is no columns for that ? Is SCD3 rule by default consider particular column type ? I do understand that these type does not consider past history, but why then its maintain past history for location ?

[@Unstoppableankit]

It Depends Based On The Requirements, He Was Just Explaining How We Can Track Of Any Column And Took Location As Tracking Point.

[@vartikathakur4273]

Hi Vivek, Your video was very helpful. Just one query. In case of SCD 2, can we have duplicate value for id??As it has 123 in all the cases.

[@TechCoach]

In SCD usually you will have a surrogate key to uniqely identify every record also you will have a start_date end_date and /or a flag to identify the old and the latest records :)

[@fahadmahmood7150]

Explanation was very precise and through the point.I really like the way you explained..!! Could you please explain the concept of granularity in depth and its significance.. Thanks in advance.!

[@ranjan25k]

wouldn't the SK which in your example appears to be ID change when you apply SCD 2? You have kept 123 for all the records in DW while applying SCD 2. As SK is also PK I don't see how it would work. Please confirm.!

[@kevinbanks7648]

You are correct in my opinion, although you would normally expect a surrogate key which will update as you say and an ID which would say the same.

[@dhanarajuramadi4733]

Thank you , keep adding more ..👍

[@TechCoach]

dhanaraju ramadi Thanks for the kind words. I will be uploading more such videos soon.

[@gaurisharma6331]

in type2 SCD the surrogate key should also change for new record.In the video it still shows key as 123 for all three records.Surrogate Key is Primary key hence there cannot be duplicates

[@Ranvir786]

Very well Explanation. Thank you so much :)

[@TechCoach]

+Ranvir singh Thanks a lot Ranvir Singh :)

[@Ahlambabes]

Thank you very much for your explanation 👍

[@TechCoach]

Thanks for the kind words :)