public interface Constraint
Constraint objects are used to determine if mutations will be applied to a table.
This interface expects implementers to return violation codes. The reason codes are returned instead of arbitrary strings to encourage conciseness. Conciseness is needed because violations are aggregated. If a user sends a batch of 10,000 mutations to Accumulo, only aggregated counts about which violations occurred are returned. If the constraint implementer were allowed to return arbitrary violation strings like the following:
Value "abc" is not a number
Value "vbg" is not a number
This would not aggregate very well, because the same violation is represented with two different strings.
Modifier and Type | Interface and Description |
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static interface |
Constraint.Environment
The environment within which a constraint exists.
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Modifier and Type | Method and Description |
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List<Short> |
check(Constraint.Environment env,
Mutation mutation)
Checks a mutation for constraint violations.
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String |
getViolationDescription(short violationCode)
Gets a short, one-sentence description of what a given violation code means.
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String getViolationDescription(short violationCode)
violationCode
- numeric violation codeList<Short> check(Constraint.Environment env, Mutation mutation)
env
- constraint environmentmutation
- mutation to checkCopyright © 2011–2016 The Apache Software Foundation. All rights reserved.