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| <html> |
| <head> |
| <title>Accumulo Constraints</title> |
| <link rel='stylesheet' type='text/css' href='documentation.css' media='screen'/> |
| </head> |
| <body> |
| |
| <h1>Apache Accumulo Documentation : Constraints</h1> |
| |
| Accumulo supports constraints. Constraints are applied to mutations at ingest time. |
| |
| <p>Implementing a new constraint is a snap. Simply write some Java code that |
| implements <code>org.apache.accumulo.core.constraints.Constraint</code>. |
| |
| <p>To deploy a new constraint, jar it up and put the jar in accumulo/lib/ext. |
| |
| <p>After creating a constraint, set a table specific property to use it. The following example adds two constraints to table foo. In the example com.test.ExampleConstraint and com.test.AnotherConstraint are class names. |
| |
| <p><pre> |
| user@instance:9999 perDayCounts> createtable foo |
| user@instance:9999 foo> config -t foo -s table.constraint.1=com.test.ExampleConstraint |
| user@instance:9999 foo> config -t foo -s table.constraint.2=com.test.AnotherConstraint |
| user@instance:9999 foo> config -t foo -f constraint |
| ---------+------------------------------------------+----------------------------------------- |
| SCOPE | NAME | VALUE |
| ---------+------------------------------------------+----------------------------------------- |
| table | table.constraint.1...................... | com.test.ExampleConstraint |
| table | table.constraint.2...................... | com.test.AnotherConstraint |
| ---------+------------------------------------------+----------------------------------------- |
| user@instance:9999 foo> |
| </pre> |
| |
| </body> |
| </html> |
