Module datarush.library
Package com.pervasive.datarush.operators.assertion

Class AssertSorted

  • All Implemented Interfaces:
    LogicalOperator, PipelineOperator<RecordPort>, RecordPipelineOperator
    public final class AssertSorted
extends ExecutableOperator
implements RecordPipelineOperator
    Verifies that the input data is sorted by the given set of keys. This represents a distributed operation if the input data is also distributed. Specifically, if the input data is distributed this verifies that each input partition is sorted. If the input data is non-distributed this verifies that the single partition is sorted. Output data will be tagged with appropriate metadata such that downstream operations can leverage the knowledge of input ordering to chose more efficient algorithms for processing.

    • Constructor Detail

      • AssertSorted

        public AssertSorted()
        Construct the operator with default settings.

      • AssertSorted

        public AssertSorted​(SortKey... ordering)
        Construct the assertion operator with the given key ordering.
        Parameters:
        ordering - expected sort order for the input

    • Method Detail

      • getOrdering

        public SortKey[] getOrdering()
        Get the expected sort ordering.
        Returns:
        expected sort order for the input

      • setOrdering

        public void setOrdering​(SortKey... ordering)
        Set the expected ordering of the input keys. If an ordering is not specified, all fields will be treated as keys using the default sort ordering of ascending.
        Parameters:
        ordering - expected sort order for the input

      • setOrdering

        public void setOrdering​(String... ordering)
        Set the expected ordering of the input keys. Sort keys are specified as field names plus an optional ordering direction, either asc or desc. For example, to sort descending by the shipdate field, "shipdate desc".
        Parameters:
        ordering - expected sort order for the input

      • getLogFrequency

        public int getLogFrequency()
        Get the log frequency.
        Returns:
        log frequency

      • setLogFrequency

        public void setLogFrequency​(int logFrequency)
        Sets the frequency with with to log. logFrequency <= 0 means log only the total number of comparisons.
        Parameters:
        logFrequency - the frequency with which to log.

      • computeMetadata

        protected void computeMetadata​(StreamingMetadataContext ctx)
        Description copied from class: StreamingOperator
        Implementations must adhere to the following contracts

        General

        Regardless of input ports/output port types, all implementations must do the following:

        1. Validation. Validation of configuration should always be performed first.
        2. Declare parallelizability.. Implementations must declare parallelizability by calling StreamingMetadataContext.parallelize(ParallelismStrategy).

        Input record ports

        Implementations with input record ports must declare the following:
        1. Required data ordering:
          2. Implementations that have data ordering requirements must declare them by calling RecordPort#setRequiredDataOrdering, otherwise data may arrive in any order.
        2. Required data distribution (only applies to parallelizable operators):
          3. Implementations that have data distribution requirements must declare them by calling RecordPort#setRequiredDataDistribution, otherwise data will arrive in an unspecified partial distribution.
        Note that if the upstream operator's output distribution/ordering is compatible with those required, we avoid a re-sort/re-distribution which is generally a very large savings from a performance standpoint. In addition, some operators may chose to query the upstream output distribution/ordering by calling RecordPort#getSourceDataDistribution and RecordPort#getSourceDataOrdering. These should be viewed as a hints to help chose a more efficient algorithm. In such cases, though, operators must still declare data ordering and data distribution requirements; otherwise there is no guarantee that data will arrive sorted/distributed as required.

        Output record ports

        Implementations with output record ports must declare the following:
        1. Type: Implementations must declare their output type by calling RecordPort#setType.
        Implementations with output record ports may declare the following:
        1. Output data ordering: Implementations that can make guarantees as to their output ordering may do so by calling RecordPort#setOutputDataOrdering
        2. Output data distribution (only applies to parallelizable operators): Implementations that can make guarantees as to their output distribution may do so by calling RecordPort#setOutputDataDistribution
        Note that both of these properties are optional; if unspecified, performance may suffer since the framework may unnecessarily re-sort/re-distributed the data.

        Input model ports

        In general, there is nothing special to declare for input model ports. Models are implicitly duplicated to all partitions when going from non-parallel to parallel operators. The case of a model going from a parallel to a non-parallel node is a special case of a "model reducer" operator. In the case of a model reducer, the downstream operator, must declare the following:
        1. Merge handler: Model reducers must declare a merge handler by calling AbstractModelPort#setMergeHandler.
        Note that MergeModel is a convenient, re-usable model reducer, parameterized with a merge-handler.

        Output model ports

        SimpleModelPort's have no associated metadata and therefore there is never any output metadata to declare. PMMLPort's, on the other hand, do have associated metadata. For all PMMLPorts, implementations must declare the following:
        1. pmmlModelSpec: Implementations must declare the PMML model spec by calling PMMLPort.setPMMLModelSpec.
        Specified by:
        computeMetadata in class StreamingOperator
        Parameters:
        ctx - the context

      • execute

        protected void execute​(ExecutionContext context)
        Description copied from class: ExecutableOperator
        Executes the operator. Implementations should adhere to the following contracts:
        1. Following execution, all input ports must be at end-of-data.
        2. Following execution, all output ports must be at end-of-data.
        Specified by:
        execute in class ExecutableOperator
        Parameters:
        context - context in which to lookup physical ports bound to logical ports