Regenerate microsoft/knowledge from upstream BCApps instructions

The previous LLM-generated knowledge files contained factual
hallucinations. The most visible was the claim that `FindFirst` /
`FindLast` "forces a full-table scan" on an unfiltered record - it does
not; those APIs return a single row via the current key.

Other inaccuracies the audit found and fixed:

* `FindSet(true)` was described as "taking a LockTable". The correct
  upstream phrasing is that `FindSet(true)` sets
  `ReadIsolation::UpdLock` on the read. UpdLock and LockTable are
  related but distinct mechanisms.
* The list of production-scale tables had been invented beyond the
  upstream source (e.g. "Detailed Cust. Ledg. Entry") without a
  citation. The regenerated list matches the ten tables upstream lists
  with their P95 row counts.
* `SetLoadFields` guidance had been augmented with an extra mechanism
  claim ("the database resolves the filter using the index without
  hydrating the value") not present in upstream.

Approach: full regeneration of `microsoft/knowledge/` from the six
upstream BCApps Code Review instruction files, with Microsoft Learn /
the AL language reference as a secondary source. Every claim in every
regenerated file is anchored to a verbatim upstream quote (or a Learn
URL); the audit trail lives in artifacts/trace-<domain>.json on the
session workspace.

The PR #11 transaction/error-handling cluster is preserved verbatim:

* performance/understand-implicit-transaction-boundary.md
* performance/codeunit-run-as-atomic-sub-operation.{md,good.al,bad.al}
* performance/codeunit-run-requires-prior-commit-inside-transaction.{md,good.al,bad.al}
* performance/use-tryfunction-for-error-catching-not-rollback.{md,good.al,bad.al}
* performance/avoid-commit-inside-loops.{md,good.al,bad.al}
* security/commitbehavior-attribute-scopes-explicit-commits.{md,good.al,bad.al}
* testing/transactionmodel-attribute-governs-test-transactions.{md,good.al,bad.al}

These articles already cite Microsoft Learn and were carefully
cross-referenced; the regeneration skips their topics rather than
duplicating them.

File counts after regeneration:

  performance   35 .md  (5 preserved + 30 new)
  privacy       17 .md
  security      18 .md  (1 preserved + 17 new)
  style         33 .md
  testing        1 .md  (preserved)
  ui            19 .md
  upgrade       18 .md

Total 141 atomic knowledge files, each strictly one rule. All pass
.github/scripts/validate_frontmatter.py with 0 errors and 0 warnings.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
This commit is contained in:
Jesper Schulz-Wedde 2026-05-21 09:53:09 +02:00
parent 613c4b4019
commit a9f3c50863
562 changed files with 6293 additions and 4869 deletions

View file

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---
bc-version: [all]
domain: style
keywords: [temporary, temp, prefix, record-variable, naming]
technologies: [al]
countries: [w1]
application-area: [all]
---
# Prefix temporary record variables with `Temp`
## Description
A `Record` variable declared with the `temporary` modifier behaves nothing like a normal record variable: it never touches the database, holds rows only for the lifetime of the variable, and is not visible to filters or queries on the underlying table. The BC convention is to make that difference visible at every call site by prefixing the variable name with `Temp``TempJobWIPBuffer`, `TempSalesLine`, `TempIntegerBuffer`. The convention is load-bearing for code review: when a reader sees `SalesLine.Insert()`, they expect a database write; when they see `TempSalesLine.Insert()`, they know it is an in-memory buffer.
## Best Practice
Every variable of type `Record X temporary` must start with `Temp`. The same applies to parameters: a procedure that receives a temporary record as a buffer names the parameter `TempBuffer`, `TempSalesLine`, and so on. The convention extends naturally to derived names — `TempJobWIPBufferCopy`, `TempSourceSalesLine` — anything that starts with `Temp` is in-memory.
See sample: `temporary-variable-temp-prefix.good.al`.
## Anti Pattern
`WIPBuffer: Record "Job WIP Buffer" temporary;` reads at the call site as if it were a database operation: `WIPBuffer.Insert()` looks identical to a write to the underlying table. The reader has to scroll back to the declaration to discover that this is in-memory, every time.
See sample: `temporary-variable-temp-prefix.bad.al`.