Package org.apache.cassandra.db

Class PartitionRangeReadCommand

    • Method Detail

      • allDataRead

        public static PartitionRangeReadCommand allDataRead​(TableMetadata metadata,
                                                    long nowInSec)
        Creates a new read command that query all the data in the table.
        Parameters:
        metadata - the table to query.
        nowInSec - the time in seconds to use are "now" for this query.
        Returns:
        a newly created read command that queries everything in the table.

      • clusteringIndexFilter

        public ClusteringIndexFilter clusteringIndexFilter​(DecoratedKey key)
        Description copied from class: ReadCommand
        The clustering index filter this command to use for the provided key.

        Note that that method should only be called on a key actually queried by this command and in practice, this will almost always return the same filter, but for the sake of paging, the filter on the first key of a range command might be slightly different.

        Specified by:
        clusteringIndexFilter in class ReadCommand
        Parameters:
        key - a partition key queried by this command.
        Returns:
        the ClusteringIndexFilter to use for the partition of key key.

      • isNamesQuery

        public boolean isNamesQuery()

      • forSubRange

        public PartitionRangeReadCommand forSubRange​(AbstractBounds<PartitionPosition> range,
                                             boolean isRangeContinuation)
        Returns an equivalent command but that only queries data within the provided range.
        Parameters:
        range - the sub-range to restrict the command to. This method assumes that this is a proper sub-range of the command this is applied to.
        isRangeContinuation - whether range is a direct continuation of whatever previous range we have queried. This matters for the DataLimits that may contain states when we do paging and in the context of parallel queries: that state only make sense if the range queried is indeed the follow-up of whatever range we've previously query (that yield said state). In practice this means that ranges for which isRangeContinuation is false may have to be slightly pessimistic when counting data and may include a little bit than necessary, and this should be dealt with post-query (in the case of StorageProxy.getRangeSlice(), which uses this method for replica queries, this is dealt with by re-counting results on the coordinator). Note that if this is the first range we queried, then the DataLimits will have not state and the value of this parameter doesn't matter.

      • getTimeout

        public long getTimeout​(java.util.concurrent.TimeUnit unit)
        Description copied from class: ReadCommand
        The configured timeout for this command.
        Specified by:
        getTimeout in class ReadCommand
        Returns:
        the configured timeout for this command.

      • isReversed

        public boolean isReversed()
        Description copied from class: ReadCommand
        Whether the underlying ClusteringIndexFilter is reversed or not.
        Specified by:
        isReversed in class ReadCommand
        Returns:
        whether the underlying ClusteringIndexFilter is reversed or not.

      • loggableTokens

        public java.lang.String loggableTokens()
        Description copied from class: ReadCommand
        Return the queried token(s) for logging
        Specified by:
        loggableTokens in class ReadCommand

      • postReconciliationProcessing

        public PartitionIterator postReconciliationProcessing​(PartitionIterator result)
        Allow to post-process the result of the query after it has been reconciled on the coordinator but before it is passed to the CQL layer to return the ResultSet. See CASSANDRA-8717 for why this exists.

      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object

      • metadata

        public TableMetadata metadata()
        Description copied from interface: ReadQuery
        The metadata for the table this is a query on.
        Specified by:
        metadata in interface ReadQuery
        Returns:
        the metadata for the table this is a query on.

      • executeInternal

        public PartitionIterator executeInternal​(ReadExecutionController controller)
        Description copied from interface: ReadQuery
        Execute the query for internal queries (that is, it basically executes the query locally).
        Specified by:
        executeInternal in interface ReadQuery
        Parameters:
        controller - the ReadExecutionController protecting the read.
        Returns:
        the result of the query.

      • limits

        public DataLimits limits()
        Description copied from interface: ReadQuery
        The limits for the query.
        Specified by:
        limits in interface ReadQuery
        Returns:
        The limits for the query.

      • nowInSec

        public long nowInSec()
        Description copied from interface: ReadQuery
        The time in seconds to use as "now" for this query.

        We use the same time as "now" for the whole query to avoid considering different values as expired during the query, which would be buggy (would throw of counting amongst other things).

        Specified by:
        nowInSec in interface ReadQuery
        Returns:
        the time (in seconds) to use as "now".

      • rowFilter

        public RowFilter rowFilter()
        Description copied from interface: ReadQuery
        Filters/Resrictions on CQL rows.

        This contains the restrictions that are not directly handled by the ClusteringIndexFilter. More specifically, this includes any non-PK column restrictions and can include some PK columns restrictions when those can't be satisfied entirely by the clustering index filter (because not all clustering columns have been restricted for instance). If there is 2ndary indexes on the table, one of this restriction might be handled by a 2ndary index.

        Specified by:
        rowFilter in interface ReadQuery
        Returns:
        the filter holding the expression that rows must satisfy.

      • columnFilter

        public ColumnFilter columnFilter()
        Description copied from interface: ReadQuery
        A filter on which (non-PK) columns must be returned by the query.
        Specified by:
        columnFilter in interface ReadQuery
        Returns:
        which columns must be fetched by this query.

      • toCQLString

        public java.lang.String toCQLString()
        Recreate the CQL string corresponding to this query.

        Note that in general the returned string will not be exactly the original user string, first because there isn't always a single syntax for a given query, but also because we don't have all the information needed (we know the non-PK columns queried but not the PK ones as internally we query them all). So this shouldn't be relied too strongly, but this should be good enough for debugging purpose which is what this is for.