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2b5550c346
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>
24 lines
1.6 KiB
Markdown
24 lines
1.6 KiB
Markdown
---
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bc-version: [all]
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domain: performance
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keywords: [maintainsqlindex, key, sift, flowfield, sum, count, table-scan]
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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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# MaintainSQLIndex = false on a key disables SIFT for FlowFields that depend on it
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## Description
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`MaintainSQLIndex = false` on a key tells the platform not to materialize that key as a SQL index. Per the upstream guidance, when a FlowField's source key carries that property, "SIFT cannot function, COUNT/SUM will table-scan." The flag is sometimes set to save write-path cost on a rarely-queried key, but if a `CalcFormula` aggregates through that exact key, the FlowField loses its index — every `CalcFields`/`CalcSums`/list-page filter that triggers it runs without one.
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## Best Practice
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When changing a key property to `MaintainSQLIndex = false`, find every FlowField whose `CalcFormula` filters on that key and verify another key covers the same fields. When adding a FlowField whose source table has only a `MaintainSQLIndex = false` key for its filter columns, add a fully-indexed key (or accept that the FlowField cannot ride SIFT and reshape the design — see `flowfield-source-key-needs-sumindexfields.md`).
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See sample: [`maintainsqlindex-false-breaks-flowfield-sift.bad.al`](maintainsqlindex-false-breaks-flowfield-sift.bad.al).
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## Anti Pattern
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A FlowField whose `CalcFormula`'s `WHERE` columns line up with a key that has `MaintainSQLIndex = false`. The schema looks correct — the key exists, the SumIndexFields are listed — but at runtime the platform has no SQL index to use, and the aggregation table-scans on every invocation.
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