opt: simplify leak-proof boolean CASE statements#96545
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DrewKimball wants to merge 1 commit intocockroachdb:masterfrom
Open
opt: simplify leak-proof boolean CASE statements#96545DrewKimball wants to merge 1 commit intocockroachdb:masterfrom
DrewKimball wants to merge 1 commit intocockroachdb:masterfrom
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This patch adds a normalization rule `SimplifyLeakproofBooleanCase` that replaces a leak-proof boolean CASE statement with an equivalent boolean expression built using `AND` and `OR` operators. This is possible when the following conditions are satisfied: 1. The CASE statement returns a boolean value. 2. The CASE statement is leak-proof. 3. The CASE condition is a *constant* boolean value (True, False, NULL). 4. Each WHEN branch returns a *constant* boolean value. Example: ``` CASE WHEN a THEN False WHEN b THEN True ELSE c END => ((a IS NOT True) AND (b OR c)) ``` See the `ConvertCaseToCondition` comment for details. This is useful for strict UDFs, which implement the argument NULL check using a CASE statement. Informs cockroachdb#96218 Release note: None
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This patch adds a normalization rule
SimplifyLeakproofBooleanCasethat replaces a leak-proof boolean CASE statement with an equivalent boolean expression built usingANDandORoperators. This is possible when the following conditions are satisfied:Example:
See the
ConvertCaseToConditioncomment for details.This is useful for strict UDFs, which implement the argument NULL check using a CASE statement.
Informs #96218
Release note: None