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Lead with a complete plugin quick start and add task-oriented usage, troubleshooting, customization, and contribution guides. Preserve the broader plugin framing, correct conflicting contract guidance, support Agents folder reviews, and align repository validation. Convert existing sample references to clickable links without changing knowledge rules. Co-authored-by: Jesper Schulz-Wedde <jesper.schulzwedde@microsoft.com> Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
28 lines
1.6 KiB
Markdown
28 lines
1.6 KiB
Markdown
---
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bc-version: [all]
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domain: performance
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keywords: [query, primary-key-cache, get, false-positive, n-plus-one, record-cache]
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technologies: [al]
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countries: [w1]
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application-area: [all]
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---
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# Query results bypass the primary-key cache
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> Contributions welcome — open a PR to refine or extend this article.
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## Description
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The Business Central server caches primary-key `Get` calls within a transaction. Query objects do not use that cache: every `Open`/`Read` goes to SQL. `avoid-get-inside-loop-on-large-table.md` is right when an unbounded inner `Get`/`FindFirst` joins two large sets. It is wrong as a blanket rewrite of repeated `Get` on the same keys. Replacing a cached `Get` with a Query that re-executes per call can be slower. This file exists so reviewers stop treating every `Get` inside a loop as a Query candidate.
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## Best Practice
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Keep `Record.Get` for repeated lookups of the same primary keys in one transaction. Use a Query when the work is a true join or aggregation that the record API would express as nested scans. Do not flag a guarded `Get` on a repeating key as an N+1 solely because a Query could express the same columns.
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See sample: [`query-results-bypass-primary-key-cache.good.al`](query-results-bypass-primary-key-cache.good.al).
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## Anti Pattern
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Rewriting a helper that `Get`s Customer by `No.` on every sales line into a Query opened inside that helper. Distinct line customers still need a lookup; repeating customers were already served from the PK cache. The Query pays SQL every time.
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See sample: [`query-results-bypass-primary-key-cache.bad.al`](query-results-bypass-primary-key-cache.bad.al).
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