bcquality/microsoft/knowledge/performance/singleton-setup-tables-need-no-access-optimization.md

bc-version	domain	keywords	technologies	countries	application-area
all	performance	singleton setup-table sales-receivables-setup general-ledger-setup setloadfields bounded	al	w1	all

Enforced singleton setup tables need no access optimization

Description

An access-pattern exemption is valid only for a table whose schema and write paths enforce at most one row for the relevant scope. A conventional blank primary key, a parameterless Get(), or a table name ending in Setup does not enforce that invariant; another primary-key value can still create another row unless insertion logic prevents it.

Best Practice

Exempt a setup read only after confirming that noncanonical keys are rejected and every supported creation path preserves the singleton. Otherwise apply ordinary access-pattern analysis, even when existing application code normally uses one blank-key record.

Anti Pattern

Treating every *Setup table or parameterless Get() as proof of bounded cardinality without checking the primary key and insertion logic.