Precedence Constraint: In SSIS Project Control Flow, a Precedence Constraint defines the workflow between two executables. The Precedence Constraint can be based on a combination of the execution results and the Evaluation of Expressions.
A Precedence Constraint has the following Constraint Options:
A Package Designer has the option of choosing between the following 4 Evaluation Operations:
1. Constraint : Have 3 values Success(Green), Failure(Red), Completion(Blue).
2. Expression: Execution of the next task depends on the evaluation result(True or False) of the expression provided.
3. Expression and Constraint: Next task in the hierarchy runs based on options selected as Value of Constraint(Success, Failure, Completion) AND evaluation result of the expression.
4. Expression or Constraint : Next task in the hierarchy runs based on options selected as Value of Constraint(Success, Failure, Completion) OR evaluation result of the expression.
Multiple Constraints: If the constrained Task has multiple constraints, you can choose how the constraints interoperate to control the execution of the constrained Task.
Options in Radio Button are:
1. Logical AND: All constraints must evaluate to TRUE.
2. Logical OR: One constraint must evaluate to TRUE
Some Important Properties of a Precedence Constraint are:
1. PrecedenceExecutable: The executable to wait on.
2. ConstrainedExecutable: The executable that will execute.
3. EvalOp: Any of the 4 Evaluation Operation explained above.
4. Expression: The expression to be evaluated.
5. Value: Succes, Failure or Completion
6. LogicalAnd: True or false
7. EvalutesTrue: Test if the precedence constraint will eavalute TRUE.
Note: The above post is based on self study and subject to be edited. Comments and Suggestions are very welcome. Thanks...
Regards,
Paras
A Precedence Constraint has the following Constraint Options:
A Package Designer has the option of choosing between the following 4 Evaluation Operations:
1. Constraint : Have 3 values Success(Green), Failure(Red), Completion(Blue).
2. Expression: Execution of the next task depends on the evaluation result(True or False) of the expression provided.
3. Expression and Constraint: Next task in the hierarchy runs based on options selected as Value of Constraint(Success, Failure, Completion) AND evaluation result of the expression.
4. Expression or Constraint : Next task in the hierarchy runs based on options selected as Value of Constraint(Success, Failure, Completion) OR evaluation result of the expression.
Multiple Constraints: If the constrained Task has multiple constraints, you can choose how the constraints interoperate to control the execution of the constrained Task.
Options in Radio Button are:
1. Logical AND: All constraints must evaluate to TRUE.
2. Logical OR: One constraint must evaluate to TRUE
Some Important Properties of a Precedence Constraint are:
1. PrecedenceExecutable: The executable to wait on.
2. ConstrainedExecutable: The executable that will execute.
3. EvalOp: Any of the 4 Evaluation Operation explained above.
4. Expression: The expression to be evaluated.
5. Value: Succes, Failure or Completion
6. LogicalAnd: True or false
7. EvalutesTrue: Test if the precedence constraint will eavalute TRUE.
Note: The above post is based on self study and subject to be edited. Comments and Suggestions are very welcome. Thanks...
Regards,
Paras
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