Data Mappers17% of the exam
Data Mapper query design and caching
How to cut Data Mapper queries with relationship notation, step order and IN filters, keep filters on indexed fields and objects to three or fewer, page within the OFFSET limit, and choose Session or Org data caching and metadata caching.
Describe the techniques to optimize Data Mapper performance, such as reducing the number of queries, efficient filtering, relationship queries, caching, and avoiding unnecessary data mapping.
~8 min read · 10 practice questions ·
What the exam expects
- Recommend relationship notation for parent fields and an extra extract step only for child records.
- Explain how an Extract chains queries per returned record, and redesign a step order that risks the SOQL limit.
- Recommend fewer objects per Data Mapper, indexed filters and sorts, and one IN-filtered call instead of one call per record.
- Explain LIMIT and OFFSET paging and the OFFSET ceiling.
- Choose Session Cache or Org Cache and a valid Time To Live, and explain metadata caching with Scale Cache or Platform Cache.
Key terms: relationship notation (a parent field path such as Account.Name in the same query); extract step (one object queried by an Extract); data cache (a stored Data Mapper response); Time To Live In Minutes (how long cached data stays); metadata cache (the stored Data Mapper definition).
Key facts
Relationship direction
- Detail
- Child-to-parent only
Parent fields
- Detail
- One step with notation: one query instead of two
Child records
- Detail
- At least two extract steps
SOQL limit
- Detail
- 100 per Apex transaction; exceeding it fails the Data Mapper
Objects per Data Mapper
- Detail
- Three or fewer
Filters and ORDER BY
- Detail
- On indexed fields; Id and Name always indexed
LIMIT
- Detail
- 1 through 50000; default 50000
OFFSET
- Detail
- Dynamic input node; 0 to 2000
Cacheable types
- Detail
- Extract, Turbo Extract, Transform (Options tab)
Time To Live
- Detail
- Minimum 5; Session max 480; Org default 1440, max 2880
Metadata with Platform Cache
- Detail
- Allocate space in the VlocityMetadata partition
Sources for this section (6)
- Relationship Notation versus Multiple Extract Stepshelp.salesforce.com (opens in a new tab)
- When to Use Multiple Extract Stepshelp.salesforce.com (opens in a new tab)
- Configure an Omnistudio Data Mapper Extracthelp.salesforce.com (opens in a new tab)
- Omnistudio Data Mapper Best Practiceshelp.salesforce.com (opens in a new tab)
- Improving Data Mapper Performance with Cachinghelp.salesforce.com (opens in a new tab)
- Configure Caching for a Data Mapperhelp.salesforce.com (opens in a new tab)
- Why does a parent field need only relationship notation while child records need another extract step on Standard Runtime?
- When can a two-step Extract fail even though each query is small?
- Which cache type and maximum Time To Live suit user-specific Data Mapper results on Standard Runtime?
- When must an admin allocate the VlocityMetadata partition?
The questions are free to read. Answers with their sources and self-grading are included with the pack.
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