Package org.apache.cassandra.db

Class SinglePartitionReadCommand

    • Method Detail

      • create

        public static SinglePartitionReadCommand create​(TableMetadata metadata,
                                                long nowInSec,
                                                ColumnFilter columnFilter,
                                                RowFilter rowFilter,
                                                DataLimits limits,
                                                DecoratedKey partitionKey,
                                                ClusteringIndexFilter clusteringIndexFilter,
                                                Index.QueryPlan indexQueryPlan)
        Creates a new read command on a single partition.
        Parameters:
        metadata - the table to query.
        nowInSec - the time in seconds to use are "now" for this query.
        columnFilter - the column filter to use for the query.
        rowFilter - the row filter to use for the query.
        limits - the limits to use for the query.
        partitionKey - the partition key for the partition to query.
        clusteringIndexFilter - the clustering index filter to use for the query.
        indexQueryPlan - explicitly specified index to use for the query
        Returns:
        a newly created read command.

      • create

        public static SinglePartitionReadCommand create​(TableMetadata metadata,
                                                long nowInSec,
                                                ColumnFilter columnFilter,
                                                RowFilter rowFilter,
                                                DataLimits limits,
                                                DecoratedKey partitionKey,
                                                ClusteringIndexFilter clusteringIndexFilter)
        Creates a new read command on a single partition.
        Parameters:
        metadata - the table to query.
        nowInSec - the time in seconds to use are "now" for this query.
        columnFilter - the column filter to use for the query.
        rowFilter - the row filter to use for the query.
        limits - the limits to use for the query.
        partitionKey - the partition key for the partition to query.
        clusteringIndexFilter - the clustering index filter to use for the query.
        Returns:
        a newly created read command.

      • create

        public static SinglePartitionReadCommand create​(TableMetadata metadata,
                                                long nowInSec,
                                                DecoratedKey key,
                                                ColumnFilter columnFilter,
                                                ClusteringIndexFilter filter)
        Creates a new read command on a single partition.
        Parameters:
        metadata - the table to query.
        nowInSec - the time in seconds to use are "now" for this query.
        key - the partition key for the partition to query.
        columnFilter - the column filter to use for the query.
        filter - the clustering index filter to use for the query.
        Returns:
        a newly created read command. The returned command will use no row filter and have no limits.

      • fullPartitionRead

        public static SinglePartitionReadCommand fullPartitionRead​(TableMetadata metadata,
                                                           long nowInSec,
                                                           DecoratedKey key)
        Creates a new read command that queries a single partition in its entirety.
        Parameters:
        metadata - the table to query.
        nowInSec - the time in seconds to use are "now" for this query.
        key - the partition key for the partition to query.
        Returns:
        a newly created read command that queries all the rows of key.

      • fullPartitionRead

        public static SinglePartitionReadCommand fullPartitionRead​(TableMetadata metadata,
                                                           long nowInSec,
                                                           java.nio.ByteBuffer key)
        Creates a new read command that queries a single partition in its entirety.
        Parameters:
        metadata - the table to query.
        nowInSec - the time in seconds to use are "now" for this query.
        key - the partition key for the partition to query.
        Returns:
        a newly created read command that queries all the rows of key.

      • create

        public static SinglePartitionReadCommand create​(TableMetadata metadata,
                                                long nowInSec,
                                                DecoratedKey key,
                                                Slice slice)
        Creates a new single partition slice command for the provided single slice.
        Parameters:
        metadata - the table to query.
        nowInSec - the time in seconds to use are "now" for this query.
        key - the partition key for the partition to query.
        slice - the slice of rows to query.
        Returns:
        a newly created read command that queries slice in key. The returned query will query every columns for the table (without limit or row filtering) and be in forward order.

      • create

        public static SinglePartitionReadCommand create​(TableMetadata metadata,
                                                long nowInSec,
                                                DecoratedKey key,
                                                Slices slices)
        Creates a new single partition slice command for the provided slices.
        Parameters:
        metadata - the table to query.
        nowInSec - the time in seconds to use are "now" for this query.
        key - the partition key for the partition to query.
        slices - the slices of rows to query.
        Returns:
        a newly created read command that queries the slices in key. The returned query will query every columns for the table (without limit or row filtering) and be in forward order.

      • create

        public static SinglePartitionReadCommand create​(TableMetadata metadata,
                                                long nowInSec,
                                                java.nio.ByteBuffer key,
                                                Slices slices)
        Creates a new single partition slice command for the provided slices.
        Parameters:
        metadata - the table to query.
        nowInSec - the time in seconds to use are "now" for this query.
        key - the partition key for the partition to query.
        slices - the slices of rows to query.
        Returns:
        a newly created read command that queries the slices in key. The returned query will query every columns for the table (without limit or row filtering) and be in forward order.

      • create

        public static SinglePartitionReadCommand create​(TableMetadata metadata,
                                                long nowInSec,
                                                DecoratedKey key,
                                                java.util.NavigableSet<Clustering<?>> names)
        Creates a new single partition name command for the provided rows.
        Parameters:
        metadata - the table to query.
        nowInSec - the time in seconds to use are "now" for this query.
        key - the partition key for the partition to query.
        names - the clustering for the rows to query.
        Returns:
        a newly created read command that queries the names in key. The returned query will query every columns (without limit or row filtering) and be in forward order.

      • create

        public static SinglePartitionReadCommand create​(TableMetadata metadata,
                                                long nowInSec,
                                                DecoratedKey key,
                                                Clustering<?> name)
        Creates a new single partition name command for the provided row.
        Parameters:
        metadata - the table to query.
        nowInSec - the time in seconds to use are "now" for this query.
        key - the partition key for the partition to query.
        name - the clustering for the row to query.
        Returns:
        a newly created read command that queries name in key. The returned query will query every columns (without limit or row filtering).

      • 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.

      • 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.

      • forPaging

        public SinglePartitionReadCommand forPaging​(Clustering<?> lastReturned,
                                            DataLimits limits)
        Description copied from interface: SinglePartitionReadQuery
        Returns a new SinglePartitionReadQuery suitable to paging from the last returned row.
        Specified by:
        forPaging in interface SinglePartitionReadQuery
        Parameters:
        lastReturned - the last row returned by the previous page. The newly created query will only query row that comes after this (in query order). This can be null if this is the first page.
        limits - the limits to use for the page to query.
        Returns:
        the newly create query.

      • queryMemtableAndDisk

        public UnfilteredRowIterator queryMemtableAndDisk​(ColumnFamilyStore cfs,
                                                  ReadExecutionController executionController)
        Queries both memtable and sstables to fetch the result of this query.

        Please note that this method: 1) does not check the row cache. 2) does not apply the query limit, nor the row filter (and so ignore 2ndary indexes). Those are applied in ReadCommand.executeLocally(org.apache.cassandra.db.ReadExecutionController). 3) does not record some of the read metrics (latency, scanned cells histograms) nor throws TombstoneOverwhelmingException. It is publicly exposed because there is a few places where that is exactly what we want, but it should be used only where you know you don't need thoses things.

        Also note that one must have created a ReadExecutionController on the queried table and we require it as a parameter to enforce that fact, even though it's not explicitlly used by the method.

      • selectsFullPartition

        public boolean selectsFullPartition()
        Description copied from interface: ReadQuery
        Checks if this ReadQuery selects full partitions, that is it has no filtering on clustering or regular columns.
        Specified by:
        selectsFullPartition in interface ReadQuery
        Returns:
        true if this ReadQuery selects full partitions, false otherwise.

      • toString

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

      • loggableTokens

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

      • 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.