✅ 1. What is UNION and UNION ALL in SQL? Which one shows duplicate values?
UNION combines data from two SQL query results and removes all duplicate records. No matter how many duplicates exist in both tables, UNION only shows unique rows.
UNION ALL also combines data from two SQL results, but it does not remove duplicates. Every record, including duplicates, appears in the final result.
✅ If the interviewer asks:
"Which one shows duplicate values?" → Answer: UNION ALL
✅ 2. What is Decision Split and Engagement Split in Journey Builder?
Decision Split checks data from a Data Extension and sends people down different journey paths based on rules or values stored in your data.
Example: Country = “USA” → send Email A, Country = “India” → send Email B.
It is based on data.
Engagement Split checks whether subscribers interacted with your previous email in the journey.
Example: If user opened the last email → Yes Path; if not → No Path.
It is based on user behaviour (opens/clicks).
✅ 3. What are the different ways data can enter a Journey in Journey Builder?
Data can enter a journey in four ways:
Data Extension Entry (most common)
→ Contacts enter based on schedule or automation.API Event Entry
→ Contacts enter in real-time triggered by API call.Salesforce Data Event (only when Marketing Cloud Connect is enabled)
→ Enters when a Lead/Contact is created or updated in CRM.CloudPages Form / Smart Capture Form
→ User fills a form, gets inserted into a DE, and journey starts.
✅ 4. What is the difference between Lookup() and LookupRows() in AMPscript?
Lookup() returns only one value.
You give it: Data Extension name, column, and value you’re searching for, and it returns a single matching value.
LookupRows() returns multiple rows that match the filter.
Used when you expect more than one result.
In simple terms:
Lookup() = one value
LookupRows() = many rows
✅ 5. How do you connect Salesforce CRM with Marketing Cloud? (Marketing Cloud Connect)
Steps to connect:
Install Marketing Cloud Connect Package in Salesforce CRM.
Create Integration User in CRM and enable required permissions.
In SFMC, configure API user + SSO + OAuth connection.
Map CRM business units with SFMC business units.
Once connected:
CRM data is available inside Journey Builder.
You can send emails from CRM using "Send via Marketing Cloud."
✅ 6. What are the types of Data Extensions in SFMC?
SFMC has three types of Data Extensions:
Type | What it does |
|---|---|
Standard DE | Created manually, used to import or store data. |
Filtered DE | Created by filtering data from another DE. |
Random DE | System randomly selects records from another DE. |
All Data Extensions work like database tables inside SFMC.
✅ 7. What are Data Views in SFMC? How long do they store data? Most common views?
Data Views are hidden system tables inside SFMC that store email tracking data automatically.
⏳ Data retention period:
Most Data Views store data for 6 months (180 days).
⭐ Most used Data Views:
_Sent→ who received the email_Open→ who opened the email_Click→ who clicked links_Bounce→ delivery failed_Unsubscribe→ who unsubscribed
These Data Views are used in SQL queries for reporting and dashboards.
✅ 8. What is the difference between ID and Class in HTML?
ID | Class |
|---|---|
Used only once on a page | Can be used multiple times |
Called with | Called with |
Example:
#header(only one header).button(many buttons)
✅ 9. What is Inline CSS and External CSS?
Inline CSS is written inside the HTML tag and affects only that element.
Example: <p style="color: red;">Hello</p>
External CSS is kept in a separate .css file and applies styles to the entire page.
In SFMC emails, inline CSS is preferred because email clients strip external CSS.
✅ 10. What is Export Activity in Automation Studio?
Export Activity takes data from a Data Extension and exports it to FTP (or external systems) as a file.
Used when you need to share data or send reports.
Example: Export a list of users who clicked a campaign and send it to sales team.
✅ 11. Where do we use WHERE and HAVING in SQL?
WHERE filters data before grouping.
HAVING filters data after grouping (used with COUNT, SUM, etc.).
Example:
WHERE = “Show only records from India.”
HAVING = “Show only those countries where clicks > 100.”
✅ 12. What is Import Activity in Automation Studio?
Import Activity takes data from a file (CSV/FTP) and loads it into a Data Extension.
Used for daily scheduled imports or CRM/data warehouse sync.
✅ 13. How do you make an email responsive?
To make emails responsive:
Use media queries
Build emails using tables, not divs
Avoid heavy images and long widths
Use mobile-friendly font and padding
By using inline css more often
Emails adjust automatically on mobile, tablet, and laptop.
✅ 14. How do you remove duplicate records while sending emails?
You can remove duplicates by:
Using DISTINCT in SQL queries
Enabling deduplication during import
Using Subscriber Key (unique identifier)
SFMC will not send two emails to the same Subscriber Key.
✅ 15. What is the difference between Suppression List vs Publication List?
A Suppression List stops emails from going to certain people. If their email is added to the suppression list, Marketing Cloud will block the send, even if they are in your audience list.
A Publication List helps manage opt-ins and opt-outs for different types of emails (e.g., newsletters vs. product updates). Subscribers can unsubscribe from one type without leaving all emails.
✅ 16. Can a Data Extension from Business Unit 1 be accessed in Business Unit 2?
No — Data Extensions are not shared between Business Units by default.
To share, the DE must be placed in:
➡️ Shared Data Extensions (in Parent BU)
Only then, BU2 can use it.
✅ 17. What is the Syntax for AMPscript?
AMPscript is used to personalize emails.
We write variables and logic inside:
%%[
VAR @name
SET @name = AttributeValue("FirstName")
]%%
Hello %%=v(@name)=%%
VAR→ declare variableSET→ assign valuev()→ print the value
✅ 18. What are Attribute Groups in SFMC?
Attribute Groups are collections of related Data Extensions in Contact Builder.
They help connect different data tables using relationships — usually by Contact Key — so SFMC treats them as one customer profile.
In simple words: Attribute Groups = linking Data Extensions to build a 360° customer view.
✅ 19. How do you combine two Data Extensions in SFMC?
You combine Data Extensions using a SQL Query Activity in Automation Studio.
Example:
SELECT * FROM DE1
UNION
SELECT * FROM DE2
UNIONremoves duplicatesUNION ALLkeeps duplicates
👉🏻 SQL is the only way to merge data into a new DE.
✅ 20. If a user opts-in from a form, will their details be added to All Subscribers?
Yes — if you send an email to that contact using Email Studio, SFMC automatically adds them to All Subscribers List, even if they were not there before.
👉🏻 Any email send adds a subscriber to All Subscribers automatically.
✅ 21. What is Path Optimization in Journey Builder?
Path Optimization tests multiple customer paths in a Journey and automatically picks the path with better engagement (open, click, conversion).
👉🏻 It’s like an A/B test inside a Journey — SFMC chooses the winning path.
✅ 22. What is Send Classification in SFMC?
Send Classification defines what type of email is being sent — Commercial (marketing emails that require unsubscribe) or Transactional (system/alerts that don’t require unsubscribe link).
It also controls Sender/Delivery Profiles.
👉🏻 Simple: Send Classification decides what type of email you are sending and how it is sent.
✅ 23. What is Journey Re-Entry?
Re-entry defines whether a contact can enter the same journey more than once.
There are 3 modes:
No Re-entry → Contact enters only once
Re-entry Anytime → Can enter multiple times
Re-entry only after exiting → Can enter again only after the first journey finishes
👉🏻 Re-entry decides how many times a person can go through a journey.
✅ 24. What is Send Throttle?
Send Throttle slows down email sending by sending emails in controlled batches instead of blasting all at once.
Used to protect domain/IP reputation and reduce sudden traffic spikes.
👉🏻 Helps avoid deliverability issues by sending emails slowly and safely.
✅ 25. What is a Contact Key / Subscriber Key?
Contact Key (or Subscriber Key) is the unique identifier for each customer in SFMC.
It's used to track the same person across multiple channels (email, SMS, push).
👉🏻 Rule: Contact Key must be unique, consistent, and never reused.
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