Data Modeling and Management20% of the exam
Field types and safe field type conversion
How to pick the right custom field type for text, identifiers and locations, which type conversions lose data or are blocked, how to work around a formula reference, the 85 million conversion limit for deployments, and the picklist and global value set limits that decide when a lookup is the better design.
Given a scenario, determine the considerations when selecting or changing a field data type.
~7 min read · 15 practice questions ·
What the exam expects
- Choose a custom field type from the data: length, formatting, leading zeros, location, generated numbers.
- Predict which conversions can lose data, and what else breaks when data is lost.
- Recognise conversions Salesforce blocks, and the workaround for a field referenced in a formula.
- Explain the 85 million conversion limit on deployments and package upgrades.
- Apply picklist, multi-select and global value set limits, and know when a lookup beats a picklist.
Key terms:
- Field type conversion: changing an existing custom field's data type; it runs in the background.
- Restricted picklist: accepts only admin-defined values, even through the API.
- Global value set: a restricted value list shared by picklist fields on many objects.
- Compound field: one field made of several stored parts, such as Geolocation.
Key facts
Text and Text Area
- Detail
- Up to 255 characters
Text Area (Long)
- Detail
- 256 to 131,072 characters; default 32,768
Number
- Detail
- Leading zeros are removed
Geolocation
- Detail
- Counts as three custom fields
Auto Number
- Detail
- Max 30 characters; Text converts to it without data loss
Long text to Text
- Detail
- Truncated to the first 255 characters
After data loss
- Detail
- List views on the field are deleted
Lead-mapped field
- Detail
- Its type can't be changed
Deployment limit
- Detail
- 85 million custom field type conversions
Restricted picklist
- Detail
- 1,000 values, active and inactive combined
Global value set on over 13 objects
- Detail
- Deactivate only; no replace or delete
Multi-select import
- Detail
- Imported value replaces current selections
- Why does a Geolocation field use more of an object's field limit than a Text field?
- When can a Text field become Auto Number without losing data?
- What happens to images after a rich text field becomes a long text area?
- Why can a package upgrade that changes field types fail on a large object?
The questions are free to read. Answers with their sources and self-grading are included with the pack.
Keep reading with the Platform App Builder pack
- Core concepts
- Exam traps
- Worked scenario
The pack includes:
- All 26 lessons of the Platform App Builder guide, with reading progress
- Interactive decision walks and step-by-step sequence steppers
- Inline practice questions and one-click topic practice (15 questions for this lesson)
- An official source cited for every claim
- An AI tutor that answers from the guide
- Unlimited timed practice exams