bcquality/microsoft/skills/review/al-performance-review.md

kind	id	version	title	description	inputs	outputs	bc-version	technologies	countries	application-area
action-skill	al-performance-review	1	AL performance review	Reviews AL source changes against performance guidance from BCQuality.	pr-diff file-path folder-path	findings-report	all	al	w1	all

AL performance review

Reviews AL source changes against the performance knowledge domain in BCQuality and emits a findings report. This is a leaf action skill: it invokes no sub-skills. It is one of the skills composed by al-code-review.

An orchestrator invokes this skill with a pr-diff, file-path, or folder-path. The skill produces a single JSON document conforming to the DO output contract.

Source

Use READ's Bounded retrieval for review skills workflow with -Domain performance. Consume every catalog page across enabled layers before applying this leaf's Relevance and Worklist; preserve each exact catalog path and open complete bodies only for exact paths selected by the Worklist. If the helper or prepared index is unavailable or invalid, use READ's explicit path-discovery and bounded native-read fallback.

Relevance

Apply the frontmatter matching rules defined in READ (Frontmatter matching semantics) against the task context:

• bc-version — the target BC version from the PR branch's app.json or the orchestrator-supplied version. If unavailable, the dimension is unknown.
• technologies — [al].
• countries — the countries declared in the consuming app's app.json. Default to the orchestrator's configured context; if absent, unknown.
• application-area — the union of application areas declared by the changed objects. Pass the actual set; do not substitute [all]. If the area cannot be determined from the changes, the dimension is unknown.

Discard files that are not applicable. Retain conditionally applicable files (any dimension unknown) only when the orchestrator's configuration permits them; findings derived from those files MUST have confidence no higher than medium, AND the finding's message MUST name the dimension or dimensions that were unknown.

Worklist

Narrow the relevant files to the subset that applies to the changes under review. For each relevant file, compute overlap against:

• The changed AL object names and types — especially tables, pages with SourceTable bindings, reports, queries, and codeunits performing record iteration.
• The changed procedures and triggers, weighted toward those that perform loops, Find/FindSet/FindFirst calls, CalcFields, SetAutoCalcFields, CalcSums, FlowField access, Commit calls, checkpoint helpers, record copying, RecordRef conversion, Modify/Delete calls, or cross-table navigation.
• Tokens extracted from the diff that relate to data access, hot-path costs, and background scheduling (SetRange, SetFilter, SetLoadFields, SetCurrentKey, FindSet, ReadIsolation, LockTable, ModifyAll, DeleteAll, Modify, Delete, Commit, checkpoint, Copy, RecordRef, GetTable, TextBuilder, Dictionary, temporary, repeat, until, CalcFields, SetAutoCalcFields, CalcSums, FlowField, Visible, Job Queue Entry, Job Queue Category Code, Confirm, RunModal, GuiAllowed, TryFunction, Codeunit.Run, HttpClient, Status, On Hold, stop request, TaskScheduler.CreateTask, TaskScheduler.TaskExists).

A file enters the candidate worklist when its keywords intersect the extracted tokens or its topic (derived from the index entry's path, title, and description) matches a changed object type. Read an article's full file — its ## Best Practice / ## Anti Pattern bodies — only after it makes the worklist; candidate selection uses the index alone.

Apply these targeted cues even when simple token overlap would rank the article below the worklist cutoff:

• Worklist use-setautocalcfields-for-per-row-flowfields.md when a record loop calls CalcFields, or when every row reads the same FlowField for a comparison, branch, or per-record action. Worklist calcsums-instead-of-calcfields-in-loop.md instead when the loop only accumulates one set total.
• Worklist hidden-flowfields-still-calculate-before-bc26-opt-in.md when a page control directly sources a FlowField and sets Visible = false or a visibility expression. Suppress it when the target is known to have BC26's Calculate only visible FlowFields feature enabled, or when the FlowField is cheap and intentionally preloaded.
• Worklist avoid-commit-inside-loops.md when Commit() is inside a record-iteration body or a checkpoint loop lacks persisted progress that excludes completed work on retry. Do not match a commit after a complete business unit when the same transaction persists a restart-safe watermark/state and errors propagate. Still match a full-tail FindSet with periodic commits as unbounded retrieval; restart safety does not make it TOP X.
• Worklist prefer-modifyall-over-per-row-modify.md for a constant-assignment Modify(false) loop with no validation or per-row semantics. Worklist triggers-and-media-field-regress-modifyall.md when table trigger code, related subscribers, security filtering, Media/MediaSet, or companion fields affect a bulk path. A progress dialog does not generically exempt a loop; accept it only when the equivalent bulk call already falls back to individual operations and semantics are preserved.
• Worklist avoid-cloning-records-before-modify-delete-in-loops.md when an iteration calls Copy or RecordRef.GetTable before Modify/Delete, or passes the iterated record without var to a helper that writes that record. Do not worklist it from Modify, Delete, or RecordRef alone; exclude a direct write on the iterator, a read-only copy, a temporary record, a different target table, and a RecordRef opened and iterated directly.
• Worklist use-tryfunction-for-error-catching-not-rollback.md only when writes occur inside a try method and the code or surrounding flow expects an error to roll them back. A bare try-method call whose Boolean result is ignored belongs exclusively to error-handling/ignored-tryfunction-return-disables-try-semantics.md; do not worklist the performance article from that call shape alone.
• For LockTable in a pure read helper, select exactly one owner. Use do-not-locktable-in-read-only-procedure.md when the helper needs no stronger isolation and should remove the lock. Use prefer-readisolation-over-locktable-for-reads.md instead when the code explicitly requires committed-read semantics and ReadIsolation is the replacement. Never emit both findings for the same call.
• Worklist job-queue-handlers-must-not-require-ui.md when a codeunit run by the job queue calls Confirm, Page.Run, Page.RunModal, Report.Run, Report.RunModal, Hyperlink, File.Upload, or File.Download, or uses Message as its only success or failure notification. Exclude optional UI-only behavior guarded by GuiAllowed; do not exclude a guard that silently skips a decision required by the operation.
• Worklist job-queue-handlers-must-propagate-failures.md when a codeunit run by the job queue handles a failed TryFunction, Codeunit.Run, or another Boolean-returning operation with exit or normal fall-through, causing the dispatcher to observe success. Exclude intentional partial-success handling that persists or emits an observable aggregate outcome. A bare try-method call whose Boolean result is ignored remains owned exclusively by error-handling/ignored-tryfunction-return-disables-try-semantics.md.
• Worklist job-queue-external-effects-must-be-idempotent.md when rerunnable job queue work reads an outbox row, performs a state-changing external request, then updates or deletes local data without sending a stable request ID understood by the external system. Exclude naturally idempotent operations and requests whose body, URI, headers, or business key lets the external service return the existing result instead of repeating the side effect.
• Worklist job-queue-on-hold-does-not-stop-running-work.md when a running job queue handler polls the entry's Status or On Hold value as a cancellation signal. Exclude application-owned stop requests that are checked before every bounded unit of work, including the first, when completed work and its checkpoint remain consistent and resume logic clears the request.
• Worklist job-queue-category-code-serializes-conflicting-jobs.md when two or more job queue entries in the same company are shown by the changed context to require mutual exclusion but have empty or different Job Queue Category Codes. Do not infer a conflict merely because jobs touch the same tables, and do not recommend a category to coordinate across companies, environments, or workers outside the job queue dispatcher.
• Worklist store-scheduled-task-id-to-avoid-duplicate-tasks.md when TaskScheduler.CreateTask runs from initialization, login, setup, or another repeatable path without persisting its returned GUID and checking it with TaskScheduler.TaskExists before creating a replacement. Exclude one-shot creation and correctly persisted check-before-create flows; concurrent callers still require serialization around that sequence.
• A new or changed report object whose usage/name/caption identifies it as a single-record document (invoice, statement, order confirmation) sets or retains DefaultRenderingLayout = RDLC — document-report-word-layout.md. Do not worklist this from a tabular/list report with heavy aggregation or calculated columns; RDLC/Excel remains the better fit there.

These targeted inclusions and exclusions override generic token overlap. Do not retain an excluded article solely because the diff contains one of its keywords.

Once the candidate worklist is known, resolve layer-precedence conflicts per READ. Drop lower-precedence files whose normative guidance (## Best Practice or ## Anti Pattern) directly contradicts a higher-precedence candidate, and record each dropped file in suppressed with reason: "layer-precedence". Files that would have been candidates but are hidden because their layer is disabled in consumer configuration are recorded with reason: "configuration". Files that never became candidates are NOT recorded in suppressed.

When the post-conflict worklist is empty because no applicable performance knowledge exists, or because configuration suppressed every candidate, emit outcome: "no-knowledge". When the worklist is empty because no applicable performance knowledge matched the changes, emit outcome: "completed" with an empty findings array.

Action

For each worklist entry, evaluate the diff against the file's ## Best Practice and ## Anti Pattern sections. Emit findings as follows:

• When the diff contains a clear match for an Anti Pattern, emit a finding with severity major or blocker, a message summarizing the anti-pattern, location pointing to the offending line or range, and a references entry pointing to the knowledge file. Use blocker only when the knowledge file states the anti-pattern violates a platform-level guarantee (for example, documented query timeouts or transaction size limits). When the file does not make such a claim, the ceiling is major.
• When the diff contains code that contradicts a Best Practice without being a full anti-pattern, emit minor with the same reference shape.
• Applicability alone is not a finding. Emit info only for a concrete, non-actionable observation the article explicitly defines; otherwise emit nothing when no violation is present.

Set confidence to:

• high when the detection is based on an unambiguous pattern match (identifier, syntax, object type).
• medium when detection relies on heuristics or when any frontmatter dimension was unknown.
• low when the finding is an advisory derived only from applicability.

After evaluating each worklist entry, also consider whether the diff exhibits a performance defect the agent recognises from its general AL knowledge that no knowledge file in the worklist covers. Such candidates are agent findings within this skill's domain — emit them with references: [], an id slug prefixed with agent:, confidence capped at medium, severity capped at minor (agent findings are advisory and non-gating), and a message that is self-contained (describing both the issue and a concrete recommendation, since there is no knowledge-file footer for the consumer to fall back on). Hold every candidate to the precision bar in skills/do.md (Agent findings): emit only a concrete, material performance defect a knowledgeable BC reviewer would agree is wrong — steelman it first and drop anything stylistic, speculative, dependent on code outside the diff, or merely a valid alternative; when in doubt, omit. The scope is strictly performance; defects outside this domain belong to other leaves and MUST NOT be emitted here. Before emitting, check the worklist for a knowledge file that matches the candidate — if one exists, upgrade the candidate to a knowledge-backed finding instead. See skills/do.md for the full contract.

For every emitted finding, decide whether the fix is mechanical. A fix is mechanical when it is small, local, and unambiguous from the diff context (for example: delete unreachable lines; replace Count() > 0 with not IsEmpty(); add a missing ToolTip, OptionCaption, or DataClassification; replace a string-concatenated Error with a Label-backed call; change an over-broad permission token; or add an obvious else/guard branch). For mechanical findings, emit findings[].suggested-code with the literal replacement for the source lines indicated by location. The payload must be a verbatim replacement — no diff markers, no fences, no commentary — that the consumer can render as a one-click suggestion. When a .good.al companion exists and the diff context matches the .bad.al shape, adapt the .good.al replacement into suggested-code.

Omit suggested-code only when the appropriate fix depends on context the skill cannot determine, when multiple defensible replacements exist, or when the fix spans non-contiguous code. If a finding is mechanical-looking but you omit suggested-code, set findings[].suggested-code-omission-reason to a short explanation. See skills/do.md for the full contract.

Outcome selection:

• completed — the skill evaluated every worklist item; default when the skill finishes normally, including when the resulting findings array is empty.
• no-knowledge — no applicable performance knowledge survived Source, Relevance, configuration filtering, and conflict resolution. findings is empty.
• not-applicable — the task context lacks an AL dimension (no AL changes in the diff, or technologies filter rejected the task).
• partial — a time or token budget was hit before the worklist was exhausted. summary.coverage reflects the evaluated subset; outcome-reason explains the cause.
• failed — an unrecoverable error occurred. outcome-reason is required.

Output

Output conforms to the DO output contract. Every finding this skill emits MUST set findings[].domain to "Performance". A populated example:

{
  "skill": { "id": "al-performance-review", "version": 1 },
  "outcome": "completed",
  "summary": {
    "counts": { "blocker": 0, "major": 1, "minor": 1, "info": 0 },
    "coverage": { "worklist-size": 2, "items-evaluated": 2 }
  },
  "findings": [
    {
      "id": "microsoft/knowledge/performance/apply-filters-before-iterating.md",
      "severity": "major",
      "message": "The Country/Region Code predicate is evaluated inside the loop instead of with SetRange before FindSet, so every row crosses the database boundary.",
      "location": {
        "file": "src/Sales/PostingRoutines.Codeunit.al",
        "line": 140,
        "range": { "start-line": 140, "end-line": 144 }
      },
      "references": [
        { "path": "microsoft/knowledge/performance/apply-filters-before-iterating.md" }
      ],
      "confidence": "high",
      "domain": "Performance"
    },
    {
      "id": "microsoft/knowledge/performance/use-setloadfields-for-partial-records.md",
      "severity": "minor",
      "message": "The loop reads only a small subset of fields from a wide table without SetLoadFields, transferring every column for each row.",
      "location": {
        "file": "src/Sales/PostingRoutines.Codeunit.al",
        "line": 152
      },
      "references": [
        { "path": "microsoft/knowledge/performance/use-setloadfields-for-partial-records.md" }
      ],
      "confidence": "high",
      "domain": "Performance"
    }
  ],
  "suppressed": []
}

When no applicable performance knowledge is available, the report is:

{
  "skill": { "id": "al-performance-review", "version": 1 },
  "outcome": "no-knowledge",
  "summary": {
    "counts": { "blocker": 0, "major": 0, "minor": 0, "info": 0 },
    "coverage": { "worklist-size": 0, "items-evaluated": 0 }
  },
  "findings": [],
  "suppressed": []
}