Salesforce Coding Interview with Salesforce MVP | Part 2 | By Salesforce Engineer 

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Good Interview. I tried and tested. I wrote same trigger with same handler class. I inserted 1000 records, for first batch the values are true. 1-200 true. all the batches after that are false. hence 1st true 50th true 100th true 201st false 250th false 500th false 1000th false

Point is the static variable maintain it states throughout the transaction until you set another value. The Batch size is 1000 so all updates will be synchronous and there will be only one batch thread of size 1000. Trigger consider a batch of 200 records and process it synchronously, in this case, the processing will be divided in 1000/200 = 5 and from 1st record till 200th the value will be true and after that, the value will be set to false due to the condition written outside the loop and once it is set to false it remains same until it is updated so for all the other from 201 -1000 records the value will be False. I hope it explains the answer in detail. 1st true 50th true 100th true 201st false 250th false 500th false 1000th false

All debug commands will print true, As each for loop works for batch size and after completing for loop of that batch it sets variable to false(which will be never printed), for next batch variable is again initialised to true and it will print true for complete batch. The same logic will repeat for each batch. Kindly correct me @manish if i'm forgetting something ! You are doing a great job 👍

Feel like this bro is doing more over Action than answering the manish questions. 🤣🤣🤣 seems I understand manishs bhai inner feeling

Hi Manish, Great work from your side, it will help for sa many people to get some info👍🤝 Answer for the 1st question is: As you mentioned batch size is 1000, so far myvar also static variable because for entire transaction will run in only one batch and update true for all. Thank you

Thank you Manish 🙃 your video is really helpful. I m going to share this video in my college for my junior's. 🍬 Chocolate for you...... for this video.

Great session...The answer should be 1st record update: true 50th record update: true 100th record update: true 250th record update: false 500th record update: false 1000th record update: false only for first 200 records the value of static variable will be true after that it set to false ,then for remaining records (201 to 1000) it will be false. Please correct me if am wrong.

1st true 50th true 100th true 250th true 500th true 1000th false

Good one Manish , was that guy really MVP What is qualification for MVP .. no need of practical knowledge ? .. These are some basic day to day stuff for hard core SFDC developers

Hello Mainsh, These videos interviews were really great. I do have experience few interviews and everyone is asking scenario based questions like you framed in your videos, can you help with more videos like that and also if you could suggest where do I practice more of these scenario based questions as mostly in google I am getting theory questions. Thanks!!

This is amazing , lots of learning on single video and it's interesting. Much appreciated . Please do more.

1 true 50 true 100 true 201 false 250 false 500 false 1000 false Please correct me if I'm wrong

Thanks for this Manish. As per my understanding of the concept, for the first transaction the variable value will be true, once the chunk is processed and from the second chunk the value will be false because it was initialized only once......for making all the chunks to print as true what should be the approach, please give ur thoughts on this.....

Trigger.new will hold the batch of 200 records so it maked 5 threads of 1000 records. Since myVar is static variable it will hold its state across transaction. Chunks of records and myVar value: 1-200(true) 201-399(false) 400-600(false) 601-799(false) 800-1000(false)

1st record updates : true 50 record updates : true 100 record updates : true 201 record updates : true 250 record updates : true 500 record updates : true 1000 record updates : true myVar will be true each time. This is because you did not implement the Database.Stateful interface in your class, meaning variable states are not kept from one scope to another Manish please reply

Being MVP doesn’t make you expert

For the question related to updating 1000 contacts, I don't see how that static variable is affecting the data update. I tried the same code snippet in my dev org and inserted all 1000 records and updated the email for all records to empty. The static variable becomes false after the first instance of the trigger but there is no condition check using that before email field update so why 201 st record will fail ????

I don't know if my approach makes sense, but I would choose between "After Update" and "Before Update" events based on how important it is to complete "Account Update" operation vs "Task creation". Let's say, Task creation is so crucial that Account shouldn't be updated without it. Then, I would go for "Before Update", because if "Insert Tasks" DML fails, the transaction should be terminated. But, for most practical reasons, Account update does a lot more job and it shouldn't be dependent on Task creation. In that case, we may go for "After Update", with Exception Handling for "Insert Tasks" DML.

1st true 50th true 100th true 250th false 500th false 1000th false

For the question on before and after trigger, since it is update operation it will work in before trigger also because the account ID is already present, but if it was insert operation it would not work.

basically Batch begins the transaction .. Now, it passes chunks of 200 records each time while processing the records i.e., execute method. Now, since the DML would be in execute method, the trigger will be invoked 5 times in this particulr scenario. Now comes the tricky part, trigger's handler would also be called 5times so it would initialise the value of the variable 5times. Note that the variable itself is static but it is not in the context of the separate transaction that batch's current chunk has created, so it will reset after 200records. Hence, 1-199 - TRUE 200 - FALSE 201-399 - TRUE 400 - FALSE 401-599- TRUE ...

WhoId instead of ownerId for Tasks

For Creating Tasks and Events - use WhatID and WhoID based on the respective object.

For assigning inserted account record id to what Id we have to choose " After Update" , record id value won't be available for 'before insert

Thank you Manish both the parts were really good. I have a question is there any source to learn and improve time and space complexities?!

really helpfull Manish🤩please add more to this playlist..thanks

Because you are referencing an Id field which will not be set until the record has been created, using a before trigger event will not work.

This is amazing , lots of learning on single video and it's interesting. Much appreciated .

For the batch question: 1st record update: True 50th record update: True 100th record update: True 250th record update: False 500th record update: False 1000th record update: False Anything after 200 for that matter would be false as the static variable context would be maintained and as Narendar already mentioned, trigger would run in batches of 200 even though you are running the batch class with a batch size of 1000.

Thanks for the trigger.oldMap on if condition that i never tried before.

Hi Manish : Below are my answers why true because it take 200 records in one batch and for loop run 200 times update static variable to false but again new batch of records come and static variable update to true for next instance of batch so answer are :) This answer will be true if code is written in trigger itself not in handler. 1st true 50 true 100 true 250 true 500 true 1000 true Let me know you thoughts ..

Thank u Manish.

Hi Manish, Great work, Please post more questions on trigger-based scenarios

The new task apex code will work well on before update but if the conditions were different and we had to implement for INSERT as well, it won't work on BEFORE INSERT because no commit would have taken place and we won't have an account Id to associate with the task. The question to use before or after suits better when dealing with Insert

Good stuff Manish. Would be helpful if you add more questions based on trigger scenarios,order of execution scenarios

1st true 50th true 100th true 250th true 500th true 1000th true

What was the answer of first question ?

We need answers for all questions

Hi friend, Can I be part of your Interview please

Hi Manish.. Give some more trigger based questions as they asked this more

true entire outputs

Hi Manish : for the 1st question I believe it will run in batches of 200, once the 200th record iteration is done, as per save order , another chunk will process but since the static variable value is now false, so , after 200th record it will always be false in that scope. 1st true 50 true 100 true 250 false 500 false 1000 false I may be wrong,so, when we will be getting the answer and explanation too, for the same. thanks @nads @manish for amazing video

On the first problem, if the batch size is 1000 then it would definitely print 1000 TRUEs since it will all be checked inside the LOOP even if the batch job maintain its state (Database.Stateful). Every transaction is discrete and each chunk the state of the job is reset. But if the batch size is

Hi Manish, I think it should be the below answer. Could you please verify the answer ? at least secretly :) True True True False False False

1st true 50 true 100 true 250 false 500 true 1000 true

All are false except firstone