Preparing for Apache Cassandra™ Certification

all right and hello welcome to our cassandra certification workshop i am david jones joined today by david chung so we have david squared today hello david hey david hello everybody welcome to the workshop how are you doing all right let's see all right sounds like everything looks good and such so let's go ahead and get into it i'm already seeing questions coming in the chat um i promise you um we are going to we're going to answer all these the fun questions i saw a bunch about like the coursework and and everything so we're going to take care of that so first thing though i do want to point out i'm noticing some regulars in the chat so hello to our regulars this workshop is going to be a little bit different not too different but a little bit different from what you might be used to um in in the format i'm going to explain everything that we're going to go through and do um i do just want to set you up because the purpose of this hence the name a cassandra certification workshop right so this workshop is specifically for those folks who are looking to get you know certified officially certified with apache cassandra um and so it is it's a slightly different format to support this and as always we welcome your feedback now let's first thing we want to do is get into mentee.com so if you would and i will give you a code so we are going to use mentee today uh for both the initial survey we'll ask you some questions but then the vast majority of what we're going to do today is actually going into a set of 20 practice questions again i'll explain more about that so you're going to need mentee for this piece so go to mentee.com in the code i see ah alex beat me to it thank you alex i see sean is going to beat me to it over in the discord by the way uh we should if you are on youtube that is totally fine we'll handle a youtube chat in both youtube and discord however i'm going to post the discord link here annoyingly a bunch of times the reason why i already saw some questions from some folks who said hey i can't attend the whole session or something like that you know is there a way i can contact you or is there a way i can reach out or something or where are the resources from the resources standpoint i'm going to give all of that to you just like our normal workshops this is all self-service we'll we'll talk about that however if you ever have follow-up questions things you're not clear on or something go to that discord channel because once we stop the stream for today this youtube chat's gonna go away but the discord persists and then you become part of our uh discord family if you will okay all right so we were gonna go is we're going to go to this repo i'll blow it up just a little bit hopefully it'll make it easier to read now we're not going to go through and read everything that's in here again these are built to be self-service so i know that somebody was asking earlier hey i'm going to i can't stay the full two hours what do i do go to the repo right this repo is gonna have everything you need and we also included um a practice question section that i'll show you here in a moment uh the slide deck that we're gonna go over is here in the repo as well and then all of the various links and resources that i'm referring to they are all right here right so this is a good central place as far as the practice questions go what we've noticed and in some previous runs that for some folks if you know depending on what your bit rate is set and make sure on youtube that you're set to at least 720p but if for some reason your bandwidth isn't the greatest or or you're just you know it's a little fuzzy here's what you do and i'll drop this for you as well you go to the practice questions and let me drop this down here we have all of the questions that we are going to show you today every one of them are here in the practice question section and so if for some reason the screen when we're showing them to you if it's fuzzy or something just go here and follow along we'll call out the number the question the number questions the question numbers are the same um one thing i want to point out is the answers are here but i really do ask you that when we're taking the quizzes don't look at the answer right um that is that is for when you're doing self-service to kind of check yourself all righty oh um yeah uh revis in discord if for the youtube link look at the very top of the discord main chat and the link will be right there and i see boom jack popped it anyway always in our discord the link is at the very top okay all right so hopefully all of you have that repo and if you need something with that later i have a dog barking in the background don't mind me all right so here's how we're gonna set things up right uh first thing i'm gonna bring you through i've already seen a set of questions on which certification should i take or what are they about what are the resources i'm going to bring you through that then i'm going to bring you through a bunch of steps how do you get through your certification after that we are going to then move into the practice question section right so you see this ds201 210 and 220. so what we've done and what david has really done the other david is we've taken sampling out of all the different types of questions that you can expect on the real exam now the difference with these is these are not the actual questions right that would be kind of a giveaway uh from that standpoint but they are formulated to be every bit is real as the real exam questions they are true right they're not they're not contrived or like fake or something like that they're actual real questions they're just not the questions that are on the exam right um so that's the key thing to understand uh and then after that we will finish up with some resources oh the mentee code here i'll go ahead and put the monty code i see you a a short the minty code is 34.37.065. 3437.065. there you go okay with that let's go ahead and get into the material i'm just checking for questions all right okay so the first thing which certification should you get right there are two different certifications there's the administrator and the developer certification how it breaks down is basically this if you are somebody who is looking to administrate operate or manage an apache cassandra database the administrator cert is probably for you if you are somebody who is not doing one of those things but you are say a developer or an analyst or somebody who is using apache cassandra and using the data in apache cassandra the developer certification is most likely for you now you can totally take both there's no reason why you can't do that but if you are going to focus on one or the other it really comes down to if you're going to run the thing admin if you're going to use it developer that's where that really kind of breaks down and and by the way um you'll find that in one of the resources i'm just about to get you give you there's actually some more detail on the differences between these but i think these usually kind of this kind of explains it well enough all right so the resources what resources do you have a first one at the very top and by the way i don't expect everyone to memorize these links uh these urls they're all in the slide deck that uh is in the repo and you will find that these are also in the repo itself and that readme you'll find that these links are there so this top one though is going to be datastax.com dev certifications um this is really kind of the first place to go right it's going to have explanation in there about the different paths what they are it has links to the courses and the tests themselves it also has the information you need for the exam rules and such so it's a really good place to start not only that in slash dev itself there's all sorts of learning materials that are right there in slash dev so if you haven't been there go check that out the second one is where the link i dropped a moment ago the github repo that again is going to be this kind of like single source that has all information but in particular the practice questions right those practice questions are there as well so you can kind of take them and test yourself and then third and probably the most important as far as getting you the materials that you need to actually prepare directly for the exams is academy.datastax.com i'll give you a little demo of what you need to do there academy is free by the way so you don't have to worry about you know there's no paywall credit cards or anything um and once you sign up you'll get more than just the courses uh for uh for the admin developer pads of cassandra there's actually a ton of other material that's in there for you as well okay let's see all right all right and then finally here um once you start on your journey right and you're going through a learning path you're learning more about cassandra something like that if you have follow-up questions right you know the session's going to end here after two hours but if you have follow-up questions um and you are trying to figure out something about a particular cluster an issue you're having it something you're not sure of you need clarification go to community.datastax.com we have folks all around the world who are on there who people even contributors to cassandra who were there answering those questions and the second one here and i dropped this link a little bit earlier is the discord itself right discord is actually a really um a really nice place to go if you kind of want more real time interaction you just want to chat with somebody you know we we tend to all hang out in there so you matter of fact if you take a look at the discord now you'll notice that you'll see some conversations people asking some questions about cassandra and such so again either one of these are fine if you do have like a longer form question or something it might take some research we may just point you to community because that's a better form than what we're trying to do today again ask your questions in either one of the chats and we're going to try to answer them as best we can all right let's go into these steps all right first thing as i mentioned is go to certifications um read through the material it's not a ton of content or anything like that it's not going to take you forever the key thing though i want you to take away from that is at the very bottom the exam rules and process section right these exams are proctored that means that somebody actually watches you while you take the exam not only that you can take these at any time 24 7. and what will happen is when you kick up to go take the exam somebody's actually going to come on and and they're going to proctor and they're going to watch you right there are all sorts of rules i'm going to talk about some of those rules are things like you can't have a second monitor up you know you can't have a phone in your in your in your in your view space and such right because it is in to ensure that there's no cheating and such so it is important that you read the exam rules and process that way you're not surprised when you go to take your test and you're all ready to go and you don't get anything that gets in the way okay then i saw some questions as far as like which learning path right i did talk about this a little bit um in academy there are two learning paths there's the admin learning path and the developer learning path each one of these contain all of the coursework that you need for that particular learning path right so if you're going to do the admin all you need to do is go and enroll in that and then you'll see all the coursework you need for that same thing for developer if you haven't already go to desex academy sign up again it's free that's where these learning paths are and then this is this next part is actually kind of the key piece and this is where some of you were asking questions about vouchers and such here's how you get your voucher right complete one of these learning paths so if you complete all the materials in the admin path or all the materials in the developer path um then you can get yourself your your voucher now the tests themselves without the voucher are 145 per try but with you with the voucher you get two tries right so what does that mean the two tries well that means that however you want to apply them you have two attempts so let's say that you go and take the admin exam and you pass wonderful well guess what you've got another try you could go take the developer exam and it's you still can use the voucher or let's say you try to take one of the exams but you don't pass for some reason you get another try as part of the voucher so two attempts per voucher and to get a voucher all you need to do is complete one of the learning paths once you've done so email academy datastax.com with you know your name which learning path use the email that you registered to academy with and then you'll get your voucher and by the way let me see i'm just checking the questions to see if there's anything that i need to answer okay i think we're good for the moment okay cool all right and then the last thing is take your exam right um again you know we're kind of glossing over some of this stuff just because we want to get into the practice part that's really the meat of what we're doing today but again if you want full details go to the repo that we dropped and github the data sex academy workshop cassandra certification repo and it'll have all the details that you need for everything yes thank you sean i see a question um about um the voucher right the voucher is not linked to this workshop it's linked to the completion of the learning paths one of the learning paths in academy okay so let me just go ahead and show you what this process is going to look like here we go so if you follow the link um that is here as you scroll down um one of you'll see like a data sex academy link or something like that that will bring you to academy.datastacks.com and then if you're not registered obviously you need to create an account that'll just take a moment but i am so i'm just going to sign in okay so you see something like this right you're going to see a screen that looks something like this you'll have a set of courses and such that you can take if you notice here in my catalog there's the admin learning path and the developer learning path so you pick one um now when you pick it like i said all the courses that you need will be there so for me to complete the developer learning path i'll need to complete ds101 ds201 and ds20 now once i've done that and i've gotten my voucher i've done all that then how do i take the test right um you'll notice there is a data data set certification course you click on that course and there will be some links here now you won't be able to start a test without technically getting the information about the exam rules and about doing the compatibility check but i implore all of you to just do this right up front right that way again you're not surprised if you take a look at the exam rules we're not going to go over all of them but notice things like no reference material it's closed book you have a live proctor you need a mirror right um you need a a small mirror right here um so they can inspect your you know your your physical machine all sorts of things so it is really important that you look at this first so you have all the things that you need to prepare and then that way when you're ready to go you you just go you don't have to you don't have any delays the second one is this compatibility extension now again when you actually go to take the test you'll have to do this what this is going to do this is going to check for things like do you have a second monitor you know like um other things just to ensure that your system is good um now in my case i do have a secondary screen that i'm not going to turn off right now but if i were to then you know remove that then it would move on to the next thing so do understand that you will need to install a chrome extension for this it will prompt you right i happen to have the extension installed right now but if you don't it will it'll prompt you it'll give you a link that you can use to install the extension once you've done that and you've passed a computer check and you've read the rules you're ready to go then you can go ahead and take the test now i've already signed up again sign up only takes a moment i'm going to go ahead and log in once you are logged in you will see something like this now something else to point out especially for those folks who there's at least one earlier who said hey i can't stay on the whole two hours here's another path for you to practice notice this apache cassandra sample test 20 questions it's the same 20 questions that we are we're giving you today it's the same ones are also in the github repo we're trying to give you as many ways as possible to be able to get to those practice questions so you can kind of get the feel for it once you're ready to actually take one of the exams you'll notice here you'll need to do that check right again it won't let you take the test unless you do it uh so you'll you'll be forced to do it anyway once that's good that'll light up then where it says make payment now we're giving you vouchers if you complete those learning paths right so this is how you apply it you just click on the make payment it says make payment and then have a coupon code that's it you put your voucher code in there hit apply it'll waive the fee so there won't be any charge at all and again you'll get two attempts okay and then that's it once that happens once you've had your payment in you know you've applied your voucher or whatever uh and you've passed your checks then you will get a button that will light up here on the right-hand side that will allow you to take the test and like i said you can do it 24 7 you just click on it and go and that's it you're off you'll have 90 minutes and it does tell you this here now something different about what we're going to do today during the practice questions we're actually going to give you two minutes per question and we have to do that just because we're in a two-hour workshop right in the real test you're not going to be gated on each individual question right some just take longer than more in others that's all it comes down to but you will have a total of 90 minutes so something to keep in mind but we do have to limit it today just because of the time we have all right that's it david i want to jump in with something about that sample test um when you take the sample test that is not proctored so you won't have to go you won't have to show an id and stuff like that however you will have uh it will give you a chance to see the test questions or the sample questions in the test interface so even if you go through all of the questions in this workshop i'd encourage you to go through the sample test doesn't cost anything but it lets you see what the test interface looks like and and that'll be an advantage when you take the test for real yeah that's that's a good point that's a really good point um i did see some questions come in about which email to use to get your voucher the same one that you registered with a data sex academy that is the email that you want to send to academy datasack.com when you complete a learning path oh hey david can the sample test be taken multiple times yes um you i believe you may have to register for it differently each time okay okay um i did see another question by the way i think pamela i saw your question there about um how many questions are on the i believe it's 60 but i'll show you where you can see that yourself so when you get to the test interface and you've logged in you'll see right there right yeah there's 60 questions that'll let you know how many questions are in each all right let me back out of here go to my dashboard and then go back over here okay all right let's see and i do see you guys are answering i see the chat's going that's okay cool and uh david i do see some questions about firefox other browsers oh and sean is saying yes i tested it for chrome firefox safari opera and ie edge wonderful okay so it sounds like it's metal the metal system uh supports a bunch and here's a good one a retake can be done can be taken after how many days does it have to wait at all nope there's no waiting time at all okay so duncan if that were to happen then you can just retake it again right away i would i would though suggest that if for some reason you you don't pass that you might want to take some time to study up and and kind of you know if there were sections you didn't feel comfortable with or something um you're going to want to do that first um one thing i do like i want to point out the materials in the learning paths in academy have practice quizzes right so all three of these sections ds201 210 and 220 all have practice quiz quizzes that go along with their sections if you go through all the videos and if you take all the the practice quizzes there and you feel comfortable with those you're in a pretty good place something else i should point out i kind of glossed over a second ago was when you are in academy and you're looking at one of the courses let's say if i go to ds201 you'll see so for one you'll see you have some videos some exercises but ah here's a quiz right see these quizzes but also on the right hand side there's a set of resources there i want you to point i want to point out there's lab work uh there are vms now you don't technically have to take like extra like do the exercises to pass the exams you can get all the information you need from the videos the quizzes and such however if you really want to get a much deeper level of knowledge and experience do the exercises yeah it's going to take more time but you're going to get a ton more information out of it so i just want to point out that those are there and david i want to jump in and point out one more resource that that isn't on that list and that's astra yeah that you can go into astro.datastax.com and start up a totally free account no credit card or anything required and it lets you uh log in and and play and play with cassandra without having to set it up in your local machine without having to have a download of vm or any of that stuff and i'll let you know a little secret as we were developing test questions when we wanted to test them and make sure that they actually worked and the correct answers worked and the wrong answers were really wrong my go-to was astra even though i have everything installed in my machine it was the simplest lowest barrier lowest bar way to get in into cassandra yeah you can just get in there so so especially for those of you who maybe have lower resource machines or you're bandwidth limited and you don't want to download a three gigabyte uh vm or something like that um there there's the astropath there is also catacota um i'm not gonna like i said i'm not reading through everything that's in here but you'll find there is a section down here in step five in the repo where i do point this out so you could go through all of ds201 here in catacotta and some data modeling in ds220 but we don't have the full amount of data modeling in ds220 in catacota but these are great supplemental materials and they're really nice if you have lower resource machines because catacota if you're not familiar with it it's a cloud-based system where it will spin up a session in the cloud you don't need to use the resources on your machine so those are options as well okay with that let's get in to the fun practice so again at this point i want you to take a look at your mentee and i will what's gonna happen is this i'm gonna put a question up on the page like this um once i kick off the mentee um you will have you will have two minutes i haven't started this one yet so i didn't do it you'll have two minutes to go ahead and answer and then once all the answers are in or you know the time runs out we'll go ahead and give you the we'll give you the solution right we'll explain that again in the real test you're not going to be gated you know you're not going to have a two minute limit or something we just do that because we have to here um and again if you do have any questions or anything feel free to ask all right so with that i'm going to go ahead and start this one and let me go ahead and move over here and all right so you should see a countdown and then in this case you want to consider the set of cql statements you see here and then how many rows will the roller coasters table have after executing all of the cql statements yeah sean yeah please don't answer in the chat use the mentee please [Laughter] everyone's so eager to answer those right it's okay jeffrey [Laughter] yeah and if you don't have the link for the quiz um you see alex just posted it go to mentee.com in the code 3437065 and pranjit an answer to your question no you can't use astro shell or studio during the exam the exam is closed book all right looks like the results are in so let's take a look at oh here we go the correct answer was in fact c right looks like the majority of you got it and again if you didn't get it that's okay we're gonna explain it and explain why um and before we go into the next the answer part of this one i do wanna point out like one of the things we found in doing these previous sessions that really works here is that sometimes there might be some things they're not meant to be gotchas but they're just things you need to be aware of and how the question is being asked and it's why we have picked the sampling we have so that way again when you come to the real test you kind of know what you expect all right so with that let's take a look at the answer and david can you give us an explanation yeah so if we take a look uh look at this question we've got this create table statement and right away i'm going to look at the primary key the primary key consists of a single column so that serves as both the primary key and partition key and it is the name column so now i'm going to look at the inserts and you'll notice we've got four inserts roller coasters the first one's the millennium force second one formula rasa next one steel dragon and the last one is millennium force well since that column that name column is the primary key and the partition key the two inserts the first and the last are both inserting the same primary key now in cassandra that causes an upserve remember if you come from a relational background as almost all of us do if you try to insert with the same primary key you get an error you get a key collision but in cassandra will treat that as an upsert sort of like an update if you will and what that means is that the fourth insert doesn't create a new row but it modifies the values in the row for the millennium force so now that row would say millennium four cedar point seven so instead of four rows from these four inserts we only have three because one was an upsert so the correct answer is c and most of you got that correct sorry i was reading something from patrick there and he made me laugh i almost lost it there for a moment that was really good okay yes all right good excellent all right so hopefully it kind of gives you the idea of the format so what i will do is go to question two and again for those of you who are following along in github we're on question number two and let's go ahead and start this one up pop this over okay so consider the following cql statements and what is the result of executing all of these cql statements you hmm all right looks like the results are in so let's take a look all right in this case the correct answer was d and now this one kind of got a spread across across right the available answer so let's go ahead and take a look at what happened here yeah so once again on these basic fundamental questions or foundational questions the first thing i'm going to look at is the primary key for this table you'll notice that the primary key has now two fields artist and title and since ours is the title both both in the inner circle parentheses they may make up our partition key so now the first insert the beatles in yesterday the second the beatles didn't let it be those two end up being in different partitions because the partition is defined by both columns so the beatles in yesterday is a different partition than the beatles and let it be abe and fernando is yet another partition and frank sinatra in yesterday i'll bet you didn't know that frank covered yesterday yeah but he did i'm not sure if i'm going to listen to that version myself not so much but that's yet another partition so what we end up with in this case is a table with four partitions but it was crucial to understand that artist and title together because they're in the that inner parentheses they make up the partition key so these are four unique partitions all righty all right so just a quick side note on that there it since there's no there are no clustering columns each of these partitions can only have one row all right all right just looking at yes jeffrey these questions are in fact representative of the actual exam right so now we're just at the first two questions we haven't gotten to some of the harder ones yet um for those of you who are more familiar with cassandra um so be prepared but yes they are representative they are not the same questions but they are representative of what you can expect all right so with that let's go to question number three and let me go ahead and start your quiz on this one all right so consider this cql statement and then which of the following is a valid query for the cars table yes we'll have some admin questions they'll come in a little later and to clarify on that uh these sta these questions that we're going through the first ten are are covering topics common to both the admin and the developer exam that's right so while they are not admin specific they will show questions like these will show up in the admin exam and it should be clear that when you take the admin exam you will be quizzed on both ds201 which is the core fundamentals which is this and ds210 which is the admin piece so you'll find as david just saying this first set of questions they cover the core fundamentals that both both exams have oh that's an interesting one theo what's the rate of success per exam attempt i i don't have that data i don't know if any of uh jack or if anyone does now off the top of my head the passing rate for the two exams is in the mid low 60 percent but again i'm not looking at the numbers right right in front of me okay all right looks like the answers are in let's take a look oh looks like the vast majority of you got this one right that's great so the answer the correct answer is c let's take a look at why excellent once again looking at the table definition the primary key make and model the two those two columns are the partition key and now we've added clustering columns so we're building up this idea of primary key starting simple getting more complex right away i'm going to exclude a and b because they don't they don't specify make and model which is the partition key so i can i can throw those two out the last two c and d both specify make and model and then if you look at it d says make and model in color if i look at the primary key there are two clustering columns year in color in that order and d sets a value for color but the rule is that if you're going to constrain any of the clustering columns you have to start with the first or less left most so d is not allowed because you would have to also specify the year that leaves c and c does specify the partition key make and model and the year which is the first clustering column so c is the only possible correct answer here and most of you got this right that's excellent awesome now i'm going to show leaderboard but something i want to point out about this leaderboard especially for those of you who've been with us before we're not doing swag speed does not matter in this particular case the leaderboard here is just to give you an idea of how you're doing we have 20 questions today each here is worth a thousand points on the real exam a passing grade is 70 so for today you need to get 14 000 points or more right to have passed um so we're just doing it as kind of like a gut check so you can kind of get a feel for maybe where you're at so it's not meant to be a comparison there are a ton more of you here today than the leaderboard actually shows right it only shows like the top ten so you very well could have three thousand points you're like hey why am i not there it's it's more important that you look at your phone and it'll show you where you're running mentee how many points you have that's why we're doing it okay so let's go ahead and go to question number four go ahead and pop that over there it goes and consider the cql statements or cql state a set of statements and what is a valid statement about this atomic batch [Music] uh do okay looks like the results are in and the correct answer here is c again it looks like the majority you've got this right very cool all right let's see why david yeah so once again we'll take a look at these two tables and we'll look at the the batch the batch we have two statements insert into employees and insert into employees by department we are inserting all the columns into both into both tables so the question is what's a valid statement single partition batch or multi-partition batch and is it can it be applied or not be applied so since i'm inserting into two separate tables they are two separate partitions so given that it's pretty easy to discount a and b neither of those could be the correct answer this is a multi-partition batch their final question is can it be applied well i'm inserting all of the columns into into both tables there's nothing in those inserts that's going to prevent either from being from being applied therefore the batch can be applied so it is in fact a multi-column multi-partition batch that can be applied and by process of elimination that makes the correct answer c yeah and just something to add i noticed um you know sean was making a comment there about don't don't worry if you get some of these questions wrong uh especially for those of you who are very new to cassandra or if you've not used it before some of these questions you may have no idea the that's exactly why we're doing this though right it gives you that kind of awareness of what are the types of things maybe you need to look at also what to prepare for everything that we are asking here today everything that is in the exams they are in those learning paths in academy so if you go and you take the courses that are in there you'll get all the material that you need and again you always can follow up with us on community and discord or whatever and get clarification we are totally happy to answer things for you and i'm going to answer a question real quick asked when would a batch cannot be or not be applied and the answer would be if one of the statements in the batch when for example if one of the inserts were missing uh the primary key or the partition the partition key that would fail and that would cause the entire batch to fail okay all right let's see if jeffrey has a follow-up at all or if needed okay so going on to question number five go ahead and start that for you consider the table definition with a primary key omitted here are some things that are known you really want to take read those carefully and then what primary key does this table have while that question is being answered i'm going to disappear real fast and i'll be right back [Music] do mm-hmm in an answer to the question yes uh tomorrow's session is going to be the same same workshop just offered for a different time zone it might be sleepier because it's the middle of the night for the two davids yeah it'll be 3 a.m for me and uh was it 12 a.m for me okay okay looks like the results are in let's take a look oh wow that was good so correct answer was b looks like the vast majority of everyone got that let's take a look at why yeah excellent to see everybody getting the correct answer the real question here is you look at these statements it is known that restaurant reviews are uniquely identified by a combination of name city and reviewer the primary key uniquely identifies a row so the primary key is going to include name city and reviewer all all three that doesn't that doesn't rule out any of the potential answers but the next one restaurant reviews are retrieved from the table using a combination of name and city that could mean one of two things it could mean that the partition key is one of either name or city and then the other name or city would be a clustering column or the partition key consists of name and city and if you look uh there are no cases here a b a through d where the partition there's a partition key of city so that rules out that a would be possible because name is the partition key but if we're going to retrieve by name and city city would have to be the first clustering column remember we constrain the clustering columns in order left to right so a is ruled out and name name and city has to be the partition key that leaves b is the only choice alrighty excellent so let's move on to question six again if you're following with us in the github repo uh we'll go ahead and question six here it goes so consider this table definition and the cql query which materialize view definition can be used to support the query and i believe how you pronounce your name um in answer to your question you could have had city as as the first as the first part but um that wasn't a possible answer and you know uh smith has been with us many times before and i've been saying smitha this whole time so smita let me know which way it's correct no smita what we could have come up with a correct answer with city is the partition key but we didn't because that because we needed one exactly one correct answer and multiple wrong answers or we chose to we chose to ask the question that way there are a couple of questions here that we'll have on the test that will have multiple correct answers and for those questions we'll always tell you twice we'll say choose three correct select three something like that see we will never try to trick you with that so all right looks like the results are in here and oh another spread on this one but it looks like the majority of you did in fact get this one right answer d let's see what happened [Music] okay this one's a little more complicated but we're asking we've got this table with a single simple primary key single column it's the the name column but we want to do a select on number of wins well we can't do that in this table so one of the solutions would be to create a materialized view in the materialized view we're going to want to select where wins equals four so that tells me in the materialized view that wins has to be the partition key so right away that's going to rule out a and c because name is the partition key for those materialized views so i've got b and d and you kind of just had to know this one but we could since since we're creating a materialized view is almost like a new like a new table we can't have the fields of the of the primary key be null so b would have worked except we can't have the fields of the primary key that's wins and names and wins and name be null so we must do the null check in creating the primary key therefore d as most of you got is the correct answer okay so let's go ahead and take a look at our leaderboard again it is not really for the leaderboard just kind of gut check where you are really look at your phones see how many points you have uh at this point we have taken uh six questions so the top score could be six thousand so if you're there great okay all right going on to question seven let me go ahead and start that one up for you i'm just making sure it's popping here it goes all right so consider the table definition and this sql query which secondary index can be used to support the query okay uh tez you have two minutes per question here in the minty in the real exam you won't be gated for any time per question but we have to do that here to make sure that we're keeping on track it's it's two minutes yeah yeah the real exam the only time limit is for the entire exam it sounds like for some reason ted's question got like bumped by mendy i'm not sure what's going on there oh okay and the results are in let's see what happened oh here's you know this is one of those questions that once you know this answer you're gonna be like oh oh but again if you didn't know it if you've not worked with secondary indexes you might be totally lost in this one but now you know secondary indexes are actually on uh on the exam but here you go let's hear about it yeah so if we take a take a look at this one once again we have a query that we can't run against this table the reason we can't run it is because we're we're trying to query on the cuisine field which is not um it's not a clustering column it's not part of the partition key so we're going to create a secondary index for this solution now several of you chose b that choice b would have we would have chosen city and cuisine if we were creating a materialized view but with a secondary index we're adding an index to this to this table which already has a partition a partition key which is city so we're going to create that index on the cuisine field and a is the correct answer by the way the easy the easy answer and the one that's explained here is that secondary indexes are only created on a single on a single column or field anyway but i can see why you might have chosen b if you're not familiar with this is you're thinking sort of like a materialized view but secondary index is different a is the correct answer here there you go so lesson learned only one column there's a secondary index all right moving on to question eight i'll go ahead and start that off for you all right so which descript yeah which statement describes the where clause in a query this is another one of those you just kind of once you learn it then you'll never forget it so and just a reminder the first 10 questions out of these sample questions are are representative of topics that appear on both the developer and administrator exams that's right i know it says so on the screen just want to remind people so so [Music] uh all right looks like the results are in let's take a look and the correct answer was in fact a so this again is one of those once you know it you'll never forget it yeah and we want to be careful on on this one and like any exam you do need to read carefully there is a must in all four of those answers uh where claus if we had a could these these would all be true but it says the where clause must reference all the fields of the partition key so that the and that is for the the query pattern that we're going to prefer and that is a partition per query we're going to want to nail down our query to a partition for a countably small number of partitions if we're using an n clause but either way it has to be it has to include all the fields of the partition of the partition key all right moving on to question nine and start that up for you all right so consider these cql statements and which insert statement can be used to insert a row in the people table so do this and i see there was a question about whether after taking the exam you would see the um the specific questions that you missed and the answer is cedric answered this very well as in really any any certification you don't get that you get your percentage correct and and a pass fail one other note also like pretty much any microsoft oracle amazon certification that that you take if you take it more than once you will get a different exam that there's a pool of questions and the questions that you see are randomized so mo the likelihood of getting the same exam more than once is pretty small all right let's see so the results are in the quick the correct answer was a let's go take a look at why this is another one of those that again once you know it you're like oh and then you never get it wrong again you know yeah this is a question about user defined types the the named type created up above in the beginning is a user defined type user defined types belong to a key space uh just or scopes to a key space just like tables so the people table has a field called name that is of type name that is the udt or user defined type name and what this question is really asking is do you know how to set the value of a user-defined type and as david said you kind of have to know this one and the answer is we set it using json format so a is the correct answer this one is really purely memorization yes let's go ahead and take a look at our leaderboard or again just look at your individual scores at this point we've had nine questions uh so the total points available would be nine thousand looks like we do have a set of you who are all all up in that general range and some they're really close so that's these are really good so far okay so let's go ahead into question number 10. so consider these cql statements and what is the result of executing those statements this is actually one of my favorite ones i know david laughs at me when i say that uh but you'll find out why have fun [Music] so [Music] um all right the results are in i'm so curious to see how this one went and i wondered if it was going to be a spread the correct answer is this one is one of those if you remember i said you know we're purposely giving you sampling of the types of questions you could expect and it's not they're not designed to be like gotchas or something but they are designed to kind of help you keep your eyes out for certain things that are things that you really need to actually keep your eyes out for when you're doing real data modeling and such so i will be quiet let david talk to this but this one has one that again when you learn it you'll be ah that's something i'm gonna i'm gonna keep i'm gonna keep watch for in the future yeah so we'll as i said or as david said the spread on this one was was pretty big and a b and c were the choices that that people made so second let's take a look the table definition we have a table that has a primary key consisting of two fields one partition key column column username and a clustering column email also very very very important to notice that in this table the nickname column is static so let's look at the two inserts the first insert the primary key is dc1234 and the email david datastax.com the second insert same um i'm sorry i said primary key the partition key is dc1234 second insert partition key also dc1234 so i know it's in the same partition but because the email address is different this is not an upsert so i am going to have two rows and that rules out c and d so i want to be sure about that these are two different rows because well they share the same partition key they're in the same partition they have different email values and email is a clustering column so they're different rows next there's an update and we're going to set the nickname to davey uh by the way the david squareds neither of us go by davey just just so you know um and we're going to set the description to school where the username is dc1234 and the emails david gmail.com well that's gonna set the description to school for david gmail.com and that would be answer a or b it's gonna set the nickname to davey the key here is that the nickname field is static yes so setting the field to davey for any row in this partition sets it to davey for all rows in the partition and if you were to use ss table dump the tool that lets you get a conceptual view of the of the data on disk what you would find is that the value of davey is only stored once in the partition not once any not once in each row but once for the partition as a whole so it was crucial to know uh to notice that nickname was static and then understand how how static values work since these two are both rows in the same partition they share the same value for the static static column and that makes b correct and the nickname which neither of us go by davey there's officially one person in my life who actually calls me that but it's not something i go by that's true all right so next one question 11 now this starts to change the format a little bit right we're gonna you're gonna again we're going for a sampling of the types of question that you're gonna see um so here you wanna consider the two data centers here right and then answering which is a valid statement about a read request made a consistency level of local quorum to a coordinator node z in paris dc so hmm okay so it looks like the answers are in let's take a look and wow wow that was really awesome vast majority of you got that one correct we don't have to explain it now no all right let's take a look at why is it b that was i'm really happy to see that honestly yeah that i'm excited about that too so in this case we've got two data centers and tokyo has six nodes two failed four active paris has four nodes one failed and three active and they both have a replication factor of three that that's crucial so we're making a request to to the paris data center with coordinator node z or zed so the request comes into node zed and then since the replication factor in the paris data center is three and we've made we're making this request at local quorum the requirement is that a quorum of the rep of the replicas that's a quorum of three in the paris data center have to be able to answer well a quarter of three is two and a question would be are there is there any possibility in this situation that you would not for a particular request that you would not have a quorum that is two replicas that are available and have the data in the best case scenario the replicas are x y and z and the data would exit that you're requesting exists on all three replicas no problem the worst case scenario your data is replicated on three nodes including node w which is failed so only two replicas are available but two is a quorum or majority of three so that's still sufficient even in the worst case to handle this request successfully so this request succeeds and is handled entirely within the paris dc and as almost all of you understood that means answer b is correct okay and i see if paris dc had one more failed node it it would fail right and the answer is maybe maybe not because if their data was replicated on the two remaining good notes right depends on the name it would succeed but if it your data happened to be replicated on on two of the failed nodes would fail so summer some would succeed some would fail but if only one node fails they all succeed at local quorum great question yeah and uh mariana and tej and i saw some others mention this as well i'm going to try something a little bit different with the timing of when i start the uh the the page the quiz page um so let me know if your timers give you the full two minutes this time okay all right so with that i'm gonna go ahead and go to question 12 there it is and let's see how this goes there we go okay so consider the cql traces here now something we want to point out is in the real exam you may need to scroll to see the entire trace it's not that way here but in the real exam you may need to scroll we really want to point that out for you um and then what elapsed time is the data persisted so that it will survive an unexpected node shutdown so foreign so and don't forget don't answer in the chat put your answers in the menti please and sumita i see your question about what scenario we would use the other dc well if you had just quorum the quorum would be across all nodes regardless of dc or if you had each quorum for example it would require a quorum in each dc however doing that decreases the availability meaning a failure of one of the dc's or the inability to contact it would mean you couldn't complete many requests or any requests depending on how you configure it so we're not going to do that very often local quorum is going to be um our choice in in many many cases yeah generally speaking it's a it's a good default to start at the local variance of consistency level so whether that's local quorum or local one even if you have a single data center because that way later on if you add on another data center you're in a good place you don't need to change anything from your application standpoint um and you don't have to worry about incurring what dave was just talking about where now you're trying to achieve a quorum across your data centers right so the local variants are definitely the way to start all right so the answers are in this is one of those fun ones it looks like the majority of you got to correct with answer c there you go oh excellent i'm glad i'm glad to see so many got this right because this isn't something you memorize this is having to really understand what's going on in cassandra i will repeat something that david said you'll notice it said consider the sql cql traces you may need to scroll to see the entire trace obviously on this screen you don't need to but in the test engine that we use many of you depending on your monitor size and settings will need to scroll for a couple of questions and we have stated in each question where you need to do that you may need to scroll so be careful when you see that check the interface will require you to scroll to see the entire screen all right so the question is at what elapsed time is the data persisted so that it will survive an unexpected node shutdown and the key is looking at the activities on the left execute the query parsing preparing the statement determining rep determining replications for this mutation and then there are two actions appending to commit log and adding to names mem table and this really is a question about do you know what the commit log and mem table are right and the commit log the purpose of the commit log is to store data uh in this commit log on disk so that it will survive an unexpected node shutdown the mem table in fact is in memory and will not survive a shutdown so that by the way that's why we commit to the or apply it to the commit log first so at that point we're certain that it's going to survive gets added to the mem table and the correct answer then is it is persisted and will survive when it's appended to the commit log in that in this table is 2193 milliseconds so great great job everybody okay all right going on to question 13 how is replication factor configured in cassandra do you know it's a shot if you want i can give you the uh the link i'm using for it here take a look i don't think they'll watch you play it though now that i think about it actually david the proctors are watching not listening so if you had it playing on a device that's not visible they'd never know hmm i'm glad you you all like it i've experimented with a bunch of different music during these and uh i think that the nice column the ambient stuff seems to be okay oh here you need the github link here let me give you that there you go oh sorry i just took the question off the page i'm so sorry about that let me put that back there you go okay the results are in now this is another one of those that once you know it you'll never you'll never get this wrong again the correct answer is b for key space why is that right it's configured per per key space and this is this is one that is a memory question you had to know this but if you create a couple's key spaces you will get a chance to to learn this because when you configure a key space both replication factor and strategy must be configured so if you've done this a few times you create a key space you must configure replication factory factor and the strat strategy so this was a memorization question yeah yeah and once you've ever if you've never created a key space before the moment you do your first time you'll understand how this applies because you're required to put in the replication factor and then you're like oh okay that's per key space um by the way so narayana uh and tej let me know if the way i've been doing the questions is giving you the proper amount of time i want to make sure that that's working okay so this next one is going to be our leaderboard again just look at your phones to see the tally that you have we've gotten through i want to say 13 at this point so yes if you've answered them all correctly you have 13 000 points and again you need in this exam or in this practice session you need 14 000 at minimum to pass at 70 okay so now we're gonna move over into the ds-201 piece or the ds210 i'm sorry and this is going to just be a couple questions for the admin side so what are two options for internet encryption and cassandra now notice it says choose to in a in the real exam you would then choose two of the correct answers mentee does not allow us to do that you can only choose one but if in this case if you choose either one of the correct answers you'll you'll get it correct just know in the real exam if it says choose two it means you have to choose two hmm all right answers are in and the correct answers here were c and e right so if you choose chose either c c or e you would be correct again on the exam you'd have to have chosen both c and e and let's take a look at why all right so if you look at this this is talking about inter-node encryption so it's talking about encryption between cassandra nodes in the cluster so even if i didn't know the answer i would probably rule out a because a would um be communicate would it sort of implies communication from a client to the cluster so not really internode also i might i might have thrown out d by process of elimination because uh i s we said there are two options here and d is not one of these is not like the others whereas node rack and dc are specific things in cassandra enabled is on off so they don't seem to go together that would be my thinking in this and then i'd be left with bc uh and d does node rack and dc the available options are all none dc and rack so rack and dc are the correct answers and what these mean is all encrypt communications between all nodes none means no encryption between nodes dc and rack data center means or dc means encrypted communication between data centers and rack if you're not familiar with rack rack is a logical grouping of nodes smaller than and within a data center so rack if we set the value to rack it means we encrypt communications between racks but not between nodes within the same rack so again you can narrow it down little by process of elimination but this is one you almost had to know and as david said before and i wanted to be very clear on this part of the reason we have these sample questions is to show you not just a sample of the content type of content but a sample of the question format any question that has multiple correct answers we will prompt you twice like we did here we say what are the two options and then we say choose to we don't want to make the format of the question be tricky so what are the two options choose to there are some of these questions on the exam all right all right let's go ahead and i will move over to i'm noticing um and i'm just curious if anyone else is seeing this i'm noticing at least at least one person there might be some lag between the video and the questions you're showing up on menti because if there is lag in the stream that you're viewing if it's a little behind it might look like the mentee's a little bit ahead and there sounds like there might be a disconnect between the question you're seeing and the time you have in mendy again in the real exam you're not going to be gated like this you won't have that kind of lag if you are seeing that case maybe refresh your youtube stream it might just be a little behind um because now it's kind of dawning on me why that might be the case all right so i'm going to move now to question 15 and then i will move to question 15 in mentee and i am now starting question 15 in minty which configuration file is used to set garbage collection properties for cassandra so all right looks like the answers are in and now this is again one of those you kind of need to know it uh but once you know it you'll always know it yeah so in this question one of the things that we need to make clear i don't know that we've mentioned it is that this these exams both the developer and admin certification are designed for open source cassandra version 3.x so this is not over our datastax enterprise dse product it is the open source product and it is the 3.x version just just to be certain um in this one as david said you kind of know it or don't i can see why people would have chosen cassandra.yaml yeah because cassandra.yaml if you were to ask me is the primary considerate exceedment configuration file for cassandra and we just do a lot of stuff in there but jvm options is a separate file that's pulled out and the purpose is to combine all the the jvm specific settings and that would include uh heap sizing generation uh generation sizing all of that and garbage collection so the correct answer is jvm options again cassandra yaml would be the primary configuration file but the jvm specific stuff is pulled out and i i like that it because it makes it easier to manage and configure the jvm specific java specific settings in cassandra so b is the correct answer you know i am seeing a couple things coming in from minty um one each question in menti here is a thousand points so we have a total of 20 questions uh so uh 14 000 or if you get 14 questions correct is a passing of 70 right again this is just giving you a gut of how that might compare to the real exam to pass it that same 70 yeah and sorry about that pamela it sounds like your mentee's kind of freaking out um hopefully you knew you know how many questions you got right and we can just go from there okay all right so moving on to question 16 and now moving to question 16 over and menti starting that up for you and you should see a countdown all right so consider the table definition and how a single row is stored in one men table and two ss tables on a cassandra node something you know even though this is in the admin piece this is actually something regardless if you're thinking about doing this from the development standpoint or admin is really good to know this is another one of my favorite questions it really helps you understand how cassandra is doing things under the hood oh pamela if that's the case it sounds like your video is behind so either click on live or maybe just refresh your page okay it looks like wow those are in wow that was seriously fast okay it looks like it was actually oh interesting so i you know something i think our mentee is getting a little uh messed up because it told me it was done uh but clearly it's not uh because a bunch of people haven't answered so i'm just gonna go ahead and move forward on this we'll explain it and let's see when we get to this leaderboard if it in fact uh corrects itself hopefully i don't know yeah it looks like mendy's maybe having a little bit of a problem all right so the correct answer was b all right and and as david said this this question really um gets into your understanding of how cassandra works uh because in this case we have a table we have a table definition with three fields the id field is the primary key and then we have a mem table and two ss tables right away uh where we need to know that a row can be stored across multiple mem tables i'm sorry multiple ss tables and the mem table that is the case here because in all three we have the id field of 11. then we have the score in all three and the test in the two ss tables and in cassandra the rule is the latest wins the the latest update wins well here's what i know about this i know that the latest update will be in the mem table and if you look at the time stamp it has a one three nine starts with so it it's in it's in the mem table for for score so i know the score for this row is going to be 75 and in fact that's enough to tell me uh to tell me the answer that's the only choice with the row 75 notice the the test in the bottom ss table is english where the timestamp starts at 118 and the middle one is math with the timestamp starts with 1 2 o so math which doesn't appear in the mem table is the most recent recently updated value for uh for the test column so b is the is the correct answer one note about this and what we've tried to do uh what we've what we've tried to do in the exam since this one depends on time stamps we have tried to make it clear and in this case by the third digit which time stamp comes before the other you know if you want to make this tricky you'd make the timestamps the same up until about the the sixth or seventh digit so it'd be hard to read we don't want it we don't want this to be a trick you want to be pretty easy to tell uh which one is newest so that's how this one worked and yeah the large majority of you got this one correct it's awesome okay so then um and and for those who are wondering what question we are on yes that last one we're on 16 we're just about to move to 17 i'm just going to go ahead and pop up that leaderboard so at this point the top amount of point you could have is 16 000. and i know it sounds like a couple of you had some mental questions that weren't kind of it was kind of acting a little weird um so you know obviously this isn't you're not being really tested right now right this isn't going to go down the log books or anything uh so if you keep a mental note of the questions you got right or whatever and we'll just add them up at the end all right so moving to question 17 and i will start that in minty okay so what is a valid statement about a coordinator node handling a query at consistency level three so hmm okay it looks like the answers are in and let's see oh this one was an interesting spread the correct answer was in fact d this is another one of those that um is is really good to know regardless of if you're looking to administrate a cassandra database or or on the developer end um and again it kind of hints or gives you a base understanding of how cassandra works you know how is it optimized all right so let's let's go ahead and take a look at this first off a is is not correct because we're talking about consistency level three remember what consistency level means in the case of a query or a read request it means that that three nodes have to respond before the coordinator node or three replicas have to respond before the coordinator node can send a response back to the client so if the coordinator node doesn't need to send a direct read request request to all replicas only to three uh the the coordinator node could send a direct read to three replicas but there's a better answer c is in there that there's really no reason to spend a read repair request initially d is the correct answer because what happens is the coordinator asks a single note direct read for the data it asks two other nodes to get a digest of the data why because the digest is smaller so it's less data that has to travel over the wire if these requests brings back a lot of data could be a significant performance increase also the coordinator asks the fastest node or i like to think of it as the nearest node which is the node that it's had the fastest communications with so we're trying to optimize for performance here the coordinator node then gets the data gets the digest from two other nodes creates a digest of the data it's like um like a checksum compares them and if they agree it sends the response back to the client well now what if they don't agree if they don't agree then it figures out which one has the latest timestamp because remember newest wins and has to ask that node for the newest data and sends that back to the client and sends um and that's when read repair and stuff happens but d is the correct answer we don't have to get the data from every replica we only need it and need to digest from the others okay all right so moving on to question 18 moving over to question 18 as well and minty go ahead and start that one up what is a valid statement about a right made at consistency level quorum local quorum local quorum against a key space with a replication factor of three so do all right looks like our answers are in and let's see what happened here the correct answer was in fact c this is another one of those that you know we we talk about this one in our intro to cassini like when we talk about cassandra fundamentals right we talk about this difference between replication factor and consistency level that's another reason why i like i like this question you know because it kind of really really gets at it yeah so in this one the replication factor is three meaning that cassandra will try to maintain three copies of data on replicas three replicas within uh within the cluster the consistency level is local quorum well the local quorum quorum means majority more than half the quorum of three is two so in this case cassandra will always try to write to the replication factor because that's the agreement cassandra's going to try to maintain the replication factor in this case three copies of the data three replicas within the cluster well you may say wait what about the quorum it'll it'll send the right to three nodes but as soon as two nodes acknowledge that's sufficient to meet the consistency level and it will return an acknowledgement back to the client so the correct answer here is that the coordinator will send rights to the replication factor number of nodes in this case three nodes alrighty and with that we're gonna go into our leaderboard and see where everybody is now we've only got two questions left these next two questions are going to be from the data modeling section uh so i realized we've got about five minutes we're going to go just a couple minutes over it's not going to be too bad i really really encourage you to stay with us for these because these are going to be markedly different from what you've had so far and you know especially for those of you who are taking the developer exam you're going to want to understand how these work okay so with that let's go ahead and move over to question 19. i'll start that up for you make sure we see what we should in minty here it goes all right so consider the chewbacco diagram that captures the physical data model for investment portfolio data and what is the primary key and clustering order of the table trades by and trades by a sd so do all right looks like the results are in don't mind the fire trucks coming behind me it is not for my house all right so the correct answer in this fac in this case was d and by the way if you've never come across a chewbacco diagram before welcome to tobacco diagram this is how we visualize data modeling in cassandra and and if you've not seen this before and you're like what am i looking at once you understand the pattern it's honestly not too bad um it it's a nice quick and easy way you can kind of at a glance kind of see what the data model is um so this should if anything hopefully prompt you uh for those who have to take ds220 for the data modeling piece um to to really get in there right and this tobacco diagram is a physical uh data model so it contains all the information including data types you would need to define these tables so if we look at the trip table trades by asd you see there are three fields marked in the far right side of the chevatco diagram case and c account symbol and trade id k fields marked with k are going to be part of the the partition key and those marked with c are going to be are going to be clustering columns and very very crucially here order matters for clustering columns so what this tells me right away is that the the primary key is going to be account symbol trade id and that rules out a and b they have all the right columns but they're not in the right the clustering columns are not in the right order so that leaves columns c and d by process of elimination well what is c and what's the difference between c and d you'll notice the arrow symbol is an arrow ascending trade id arrow descending so symbol column is ascending order that's the default order of clustering columns so we're going to have to set the trade id column to descending order which would make which would lead us to c possibly but remember when we did queries we said if you constrain the first clustering column i'm sorry we said if you constrain clustering columns you have to start by constraining the first one in order left to right likewise if you'd define the order of clustering columns the default is ascending but we're going to make one descending you have to define the order for all the clustering columns up until that starting at the left so it's not sufficient to just specify like c that trade id is descending we have to constrain or define the order for the previous column which is symbol making d the correct answer because it defines the clustering order for symbol even though it's the default ascending and specifies the non-default descending for the rightmost clustering column so d in this case is the correct answer well i need to check something real quick [Laughter] we didn't update our our answer slide i just realized that uh somebody pointed out that that should be this there we go oh yeah i just i just i was like oh yeah there we go that yes it should be sd yeah good good good eye by the way uh all right let's see last one last one question 20. there you go yeah thanks for pointing it out alrighty all right consider the application workflow diagram for an investment portfolio application here and which access patterns are evaluated before an application can evaluate q 3.2 do so okay so the answers are in let's see how everyone did oh look at the spread on that one um this is another one of those that um it looks more difficult than it actually is the correct answer is a and once david explains it i i hope this one's gonna really kind of hit home and give you a nice prep for the actual test yeah so the application workflow diagram is a crucial part of our data modeling and in this one we are we we do this we're extracting the queries so we have query one and if you look at it the entry point into this application workflow is query one so query one is the prerequisite for everything the first prerequisite and after query one we can execute query 2 or query 3. however query 3 is not a single query but query 3 is really multiple queries query 3 1 query 3 2 3 3 3 4 and 3 five i said and or three five so executing query three one really is executing query three exactly executing query 3.2 is really executing query three and the only prerequisite is q1 so q1 is the correct answer here a is the correct uh the correct answer because query 3 or q3 really is um one of these options 3 3.1 through 3.5 alrighty excellent thank you so much and then now let's move over to the final leaderboard again just to take a look to kind of get you get an idea of your score so at this point we had 20 questions if you got them all right you'd have 20 000 points a passing 70 percent would be 14 000. again this is just for practice just gives you a feel of of how you're doing from that standpoint um so i encourage everybody honestly to to still go study up you know unless you're unless you're already a seasoned cassandra person and you feel extremely comfortable with what you're seeing definitely definitely take a look at the um the academy resources and the quizzes in the individual courses like for ds201 ds210 or ds220 depending on which ones you're taking because those quizzes are really going to give you i mean if you can answer that stuff comfortably you're going to be in a pretty darn good place okay so then as we wrap this up um this is free form so if you have feedback positive negative constructive not so constructive if it's not constructive definitely put shawn's name in there or something but no honestly we do take this feedback seriously um anything you think we could improve things that weren't working for you um i know that some of the mentee was a little messed up for folks um and it seems like there was some stream lag for some folks as well so that's something that um we're definitely adjusting to cool and hopefully hopefully everybody got something out of this and at least i know for me when when david first came up with a set of questions and going through it um and then comparing them to actually what's on the real exam you know it it gives you such a nice sampling it kind of prepares you for some things to look out for awesome well thank you everybody for that and you can continue to put that stuff on i'm not closing menti um i do just want to close up a couple uh a couple of resources here so again take a look at datasets.comdev um it has more in there than just uh that that certifications page that i was talking about if you have particular subjects and topics that you're interested in with cassandra take the there it'll it'll bring you to the resources and actually i think one of the coolest features especially for those of you who are um looking at these particular courses is right there if you take like the developer path in slash dev the catacotta scenarios um are embedded right there so you can actually take the whole entirety of ds201 on catacoda if you wanted there are some really cool use cases i pointed them out here this data modeling one there are some really cool real world data modeling use cases in the data modeling courses in catacota again catacota is free um and if you have lower resources on your machine or just don't have the bandwidth to navigate like a three gig uh vm file or something like that it's just such a really nice uh alternative that you can you can get in and take a look and david before we go i i do want to jump in and once more with the plug for astra yeah a great resource is to open up a free astra account and start playing with the stuff especially if you're doing the dev stuff and don't want to do all the setup um great great way to try out your dev skills in in cassandra absolutely yeah as a matter of fact you'll notice if i pop over here real quick um to if you go to the repo if you go to the organization data sex academy for those of you who haven't been with us before you'll notice uh there are all sorts of other workshops like the the one we just uh we just launched this the last week or two uh for storage attach indexes or if you're looking to do things with like spring reactive or spring boot um the intro to cassandra for developers all of these are again they're free they're self-service and most of them do in fact help you get set up on astro where you can just spin up your own apache cassandra database for free right fully baked and then these workshops are designed to work with those directly for those of you who by the way came in brand new i'll go ahead and drop this because we did have a set of folks that are completely new to cassandra um i would suggest taking a look at the intro for cassandra right here um and that will that will get you going and like kind of explain to you like how do i build this stuff up how do i get the database going you know how do i do things with it okay and with that thank you everybody so much uh for coming on today and for your interaction and as always if you have any other questions you know after we stop the stream obviously the youtube chat is is going to stop we're on discord we're on community you know we're out here hit us up on linkedin if you want honestly so if you have questions clarification whatever come ask we're here and as always thank you all so much and with that take care see you david thank you everybody bye-bye and as always don't forget to click that subscribe button and ring that bell to get notifications for all of our future upcoming workshops imagine a being gifted with powers from the goddess of cassandra who grew those powers until she can multiply it will move with limitless speed and unmask hidden knowledge with those powers she was able to fully understand the connectedness of the world what she saw was a world in need of understanding from that day forward she sought to bestow her powers on all who came into contact with her empowering them to achieve wondrous feats

Channel: DataStax Developers

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Id: 1NSUXcWrkZM

Length: 125min 12sec (7512 seconds)

Published: Wed Nov 04 2020