bcquality/microsoft/knowledge/performance/use-setloadfields-for-partial-records.md
Jesper Schulz-Wedde dc14e7bb2a Update 6 knowledge articles to align with revised instructions
- performance/use-setloadfields-for-partial-records: Clarify that
  filter-only fields (SetRange/SetFilter) do not need to be listed in
  SetLoadFields — the DB resolves them via the index without hydrating
  the value into AL memory.

- performance/avoid-calcfields-in-loops: Add explicit exception for
  OnAfterGetRecord and OnValidate triggers, which are platform-managed
  and not developer-authored loops.

- performance/split-read-only-and-write-paths-to-avoid-locktable: Add
  ReadIsolation as the primary recommendation for read-only paths;
  LockTable reserved for confirmed write paths only.

- performance/prefer-direct-record-over-recordref: Scope the finding to
  hot unbounded loops (10k+ rows) over ledger-entry-scale tables;
  RecordRef in bounded/admin/setup contexts is not a concern.

- upgrade/enum-changes-must-be-additive-at-the-end: Replace direct
  ObsoleteState = Removed guidance with the two-stage workflow (Pending
  first, Removed later); reference use-obsolete-pending-before-removed.

- upgrade/use-datatransfer-for-large-dataset-initialization: Add the
  >300,000 records threshold as the concrete trigger for requiring
  DataTransfer.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
2026-04-24 10:36:08 +02:00

1.6 KiB

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Use SetLoadFields for partial records

Description

SetLoadFields instructs the platform to hydrate only the listed fields on a record variable. On wide tables, or tables with BLOB or media fields, the difference is substantial: a Sales Invoice Line has dozens of fields and loading all of them for every row of a large set is wasted bandwidth. Primary key fields, SystemId, and system audit fields are always loaded automatically. SetLoadFields works only with FieldClass = Normal; FlowFields and FlowFilters cannot be partial-loaded.

Best Practice

Call SetLoadFields before FindSet, FindFirst, or Get whenever the code path only reads a subset of fields. List every field that is read or written during the operation, including fields used in calculations and downstream function calls. Omitting a field that is later accessed triggers a second round-trip.

Fields that appear only in SetRange or SetFilter calls do not need to be included — the database resolves the filter using the index without hydrating the value into AL memory. Including filter-only fields wastes bandwidth and is not required.

See sample: use-setloadfields-for-partial-records.good.al.

Anti Pattern

Iterating a large set and reading only two or three fields without SetLoadFields forces the platform to transport every column for every row, including BLOBs and unused text fields.

See sample: use-setloadfields-for-partial-records.bad.al.