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Declare the Grain Before Writing the Query
Define what one row represents, distinguish entities from revisions and attach that meaning to keys and measures.
SQL, models & data integrity
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Original guides and technical studies, written to make the assumptions and trade-offs visible.
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5 articlesData Quality Contracts With a Defined Response
Give each data rule a scope, a null policy and an action, then keep rejected records visible in the accounting.
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Joins Without Accidental Row Multiplication
Inspect join cardinality, aggregate at the intended grain and preserve missing matches when they matter.
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Reconcile at the Same Grain
Align population, units and reporting boundaries before comparing totals, and keep missing keys distinct from value differences.
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Replayable Batch Ingestion
Separate delivery identity from business revision and make repeated input converge on a defined accepted state.
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Time and Decimal Semantics in Data Reports
Distinguish instants from local dates and define numeric units and rounding boundaries before aggregation.
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