Package org.apache.cassandra.index.internal

Class CassandraIndex

java.lang.Object
org.apache.cassandra.index.internal.CassandraIndex
All Implemented Interfaces:
Index
Direct Known Subclasses:
ClusteringColumnIndex, CollectionKeyIndexBase, CollectionValueIndex, KeysIndex, PartitionKeyIndex, RegularColumnIndex
public abstract class CassandraIndex extends Object implements Index
Index implementation which indexes the values for a single column in the base table and which stores its index data in a local, hidden table.

  • Field Details

  • Constructor Details

  • Method Details

    • supportsOperator

      protected boolean supportsOperator(ColumnMetadata indexedColumn, Operator operator)
      Returns true if an index of this type can support search predicates of the form [column] OPERATOR [value]
      Parameters:
      indexedColumn -
      operator -
      Returns:

    • buildIndexClusteringPrefix

      protected abstract <T> CBuilder buildIndexClusteringPrefix(ByteBuffer partitionKey, ClusteringPrefix<T> prefix, CellPath path)
      Used to construct an the clustering for an entry in the index table based on values from the base data. The clustering columns in the index table encode the values required to retrieve the correct data from the base table and varies depending on the kind of the indexed column. See indexCfsMetadata for more details Used whenever a row in the index table is written or deleted.
      Parameters:
      partitionKey - from the base data being indexed
      prefix - from the base data being indexed
      path - from the base data being indexed
      Returns:
      a clustering prefix to be used to insert into the index table

    • decodeEntry

      public abstract IndexEntry decodeEntry(DecoratedKey indexedValue, Row indexEntry)
      Used at search time to convert a row in the index table into a simple struct containing the values required to retrieve the corresponding row from the base table.
      Parameters:
      indexedValue - the partition key of the indexed table (i.e. the value that was indexed)
      indexEntry - a row from the index table
      Returns:

    • isStale

      public abstract boolean isStale(Row row, ByteBuffer indexValue, long nowInSec)
      Check whether a value retrieved from an index is still valid by comparing it to current row from the base table. Used at read time to identify out of date index entries so that they can be excluded from search results and repaired
      Parameters:
      row - the current row from the primary data table
      indexValue - the value we retrieved from the index
      nowInSec -
      Returns:
      true if the index is out of date and the entry should be dropped

    • getIndexedValue

      protected abstract ByteBuffer getIndexedValue(ByteBuffer partitionKey, Clustering<?> clustering, CellPath path, ByteBuffer cellValue)
      Extract the value to be inserted into the index from the components of the base data
      Parameters:
      partitionKey - from the primary data
      clustering - from the primary data
      path - from the primary data
      cellValue - from the primary data
      Returns:
      a ByteBuffer containing the value to be inserted in the index. This will be used to make the partition key in the index table

    • getIndexedColumn

      public ColumnMetadata getIndexedColumn()

    • getIndexComparator

      public ClusteringComparator getIndexComparator()

    • getIndexCfs

      public ColumnFamilyStore getIndexCfs()

    • register

      public void register(IndexRegistry registry)
      Description copied from interface: Index
      An index must be registered in order to be able to either subscribe to update events on the base table and/or to provide Searcher functionality for reads. The double dispatch involved here, where the Index actually performs its own registration by calling back to the supplied IndexRegistry's own registerIndex method, is to make the decision as to whether or not to register an index belong to the implementation, not the manager.
      Specified by:
      register in interface Index
      Parameters:
      registry - the index registry to register the instance with

    • getInitializationTask

      public Callable<?> getInitializationTask()
      Description copied from interface: Index
      Return a task to perform any initialization work when a new index instance is created. This may involve costly operations such as (re)building the index, and is performed asynchronously by SecondaryIndexManager
      Specified by:
      getInitializationTask in interface Index
      Returns:
      a task to perform any necessary initialization work

    • getIndexMetadata

      public IndexMetadata getIndexMetadata()
      Description copied from interface: Index
      Returns the IndexMetadata which configures and defines the index instance. This should be the same object passed as the argument to setIndexMetadata.
      Specified by:
      getIndexMetadata in interface Index
      Returns:
      the index's metadata

    • getBackingTable

      public Optional<ColumnFamilyStore> getBackingTable()
      Description copied from interface: Index
      If the index implementation uses a local table to store its index data, this method should return a handle to it. If not, an empty Optional should be returned. This exists to support legacy implementations, and should always be empty for indexes not belonging to a SingletonIndexGroup.
      Specified by:
      getBackingTable in interface Index
      Returns:
      an Optional referencing the Index's backing storage table if it has one, or Optional.empty() if not.

    • getBlockingFlushTask

      public Callable<Void> getBlockingFlushTask()
      Description copied from interface: Index
      Return a task which performs a blocking flush of any in-memory index data to persistent storage, independent of any flush of the base table. Note that this method is only invoked outside of normal flushes: if there is no in-memory storage for this index, and it only extracts data on flush from the base table's Memtable, then it is safe to perform no work.
      Specified by:
      getBlockingFlushTask in interface Index
      Returns:
      task to be executed by the index manager to perform the flush.

    • getInvalidateTask

      public Callable<?> getInvalidateTask()
      Description copied from interface: Index
      Return a task which invalidates the index, indicating it should no longer be considered usable. This should include an clean up and releasing of resources required when dropping an index.
      Specified by:
      getInvalidateTask in interface Index
      Returns:
      task to be executed by the index manager to invalidate the index.

    • getMetadataReloadTask

      public Callable<?> getMetadataReloadTask(IndexMetadata indexDef)
      Description copied from interface: Index
      Return a task to reload the internal metadata of an index. Called when the base table metadata is modified or when the configuration of the Index is updated Implementations should return a task which performs any necessary work to be done due to updating the configuration(s) such as (re)building etc. This task is performed asynchronously by SecondaryIndexManager
      Specified by:
      getMetadataReloadTask in interface Index
      Returns:
      task to be executed by the index manager during a reload

    • isQueryable

      public boolean isQueryable(Index.Status status)
      Description copied from interface: Index
      Check if current index is queryable based on the index status.
      Specified by:
      isQueryable in interface Index
      Parameters:
      status - current status of the index
      Returns:
      true if index should be queryable, false if index should be non-queryable

    • validate

      public void validate(ReadCommand command) throws InvalidRequestException
      Description copied from interface: Index
      Used to validate the various parameters of a supplied ReadCommand, this is called prior to execution. In theory, any command instance may be checked by any Index instance, but in practice the index will be the one returned by a call to the getIndex(ColumnFamilyStore cfs) method on the supplied command. Custom index implementations should perform any validation of query expressions here and throw a meaningful InvalidRequestException when any expression or other parameter is invalid.
      Specified by:
      validate in interface Index
      Parameters:
      command - a ReadCommand whose parameters are to be verified
      Throws:
      InvalidRequestException - if the details of the command fail to meet the index's validation rules

    • getTruncateTask

      public Callable<?> getTruncateTask(long truncatedAt)
      Description copied from interface: Index
      Return a task to truncate the index with the specified truncation timestamp. Called when the base table is truncated.
      Specified by:
      getTruncateTask in interface Index
      Parameters:
      truncatedAt - timestamp of the truncation operation. This will be the same timestamp used in the truncation of the base table.
      Returns:
      task to be executed by the index manager when the base table is truncated.

    • shouldBuildBlocking

      public boolean shouldBuildBlocking()
      Description copied from interface: Index
      Return true if this index can be built or rebuilt when the index manager determines it is necessary. Returning false enables the index implementation (or some other component) to control if and when SSTable data is incorporated into the index.

      This is called by SecondaryIndexManager in buildIndexBlocking, buildAllIndexesBlocking and rebuildIndexesBlocking where a return value of false causes the index to be exluded from the set of those which will process the SSTable data.

      Specified by:
      shouldBuildBlocking in interface Index
      Returns:
      if the index should be included in the set which processes SSTable data, false otherwise.

    • dependsOn

      public boolean dependsOn(ColumnMetadata column)
      Description copied from interface: Index
      Called to determine whether this index targets a specific column. Used during schema operations such as when dropping or renaming a column, to check if the index will be affected by the change. Typically, if an index answers that it does depend upon a column, then schema operations on that column are not permitted until the index is dropped or altered.
      Specified by:
      dependsOn in interface Index
      Parameters:
      column - the column definition to check
      Returns:
      true if the index depends on the supplied column being present; false if the column may be safely dropped or modified without adversely affecting the index

    • supportsExpression

      public boolean supportsExpression(ColumnMetadata column, Operator operator)
      Description copied from interface: Index
      Called to determine whether this index can provide a searcher to execute a query on the supplied column using the specified operator. This forms part of the query validation done before a CQL select statement is executed.
      Specified by:
      supportsExpression in interface Index
      Parameters:
      column - the target column of a search query predicate
      operator - the operator of a search query predicate
      Returns:
      true if this index is capable of supporting such expressions, false otherwise

    • customExpressionValueType

      public AbstractType<?> customExpressionValueType()
      Description copied from interface: Index
      If the index supports custom search expressions using the SELECT * FROM table WHERE expr(index_name, expression) syntax, this method should return the expected type of the expression argument. For example, if the index supports custom expressions as Strings, calls to this method should return UTF8Type.instance. If the index implementation does not support custom expressions, then it should return null.
      Specified by:
      customExpressionValueType in interface Index
      Returns:
      an the type of custom index expressions supported by this index, or an null if custom expressions are not supported.

    • getEstimatedResultRows

      public long getEstimatedResultRows()
      Description copied from interface: Index
      Return an estimate of the number of results this index is expected to return for any given query that it can be used to answer. Used in conjunction with indexes() and supportsExpression() to determine the most selective index for a given ReadCommand. Additionally, this is also used by StorageProxy.estimateResultsPerRange to calculate the initial concurrency factor for range requests
      Specified by:
      getEstimatedResultRows in interface Index
      Returns:
      the estimated average number of results a Searcher may return for any given query

    • getPostIndexQueryFilter

      public RowFilter getPostIndexQueryFilter(RowFilter filter)
      Description copied from interface: Index
      Transform an initial RowFilter into the filter that will still need to applied to a set of Rows after the index has performed it's initial scan. Used in ReadCommand#executeLocal to reduce the amount of filtering performed on the results of the index query.
      Specified by:
      getPostIndexQueryFilter in interface Index
      Parameters:
      filter - the intial filter belonging to a ReadCommand
      Returns:
      the (hopefully) reduced filter that would still need to be applied after the index was used to narrow the initial result set

    • searcherFor

      public Index.Searcher searcherFor(ReadCommand command)
      Description copied from interface: Index
      Factory method for query time search helper.
      Specified by:
      searcherFor in interface Index
      Parameters:
      command - the read command being executed
      Returns:
      an Searcher with which to perform the supplied command

    • validate

      public void validate(PartitionUpdate update, ClientState state) throws InvalidRequestException
      Description copied from interface: Index
      Called at write time to ensure that values present in the update are valid according to the rules of all registered indexes which will process it. The partition key as well as the clustering and cell values for each row in the update may be checked by index implementations
      Specified by:
      validate in interface Index
      Parameters:
      update - PartitionUpdate containing the values to be validated by registered Index implementations
      state - state related to the client connection
      Throws:
      InvalidRequestException

    • indexerFor

      public Index.Indexer indexerFor(DecoratedKey key, RegularAndStaticColumns columns, long nowInSec, WriteContext ctx, IndexTransaction.Type transactionType, Memtable memtable)
      Description copied from interface: Index
      Creates an new Indexer object for updates to a given partition.
      Specified by:
      indexerFor in interface Index
      Parameters:
      key - key of the partition being modified
      columns - the regular and static columns the created indexer will have to deal with. This can be empty as an update might only contain partition, range and row deletions, but the indexer is guaranteed to not get any cells for a column that is not part of columns.
      nowInSec - current time of the update operation
      ctx - WriteContext spanning the update operation
      transactionType - indicates what kind of update is being performed on the base data i.e. a write time insert/update/delete or the result of compaction
      memtable - current memtable that the write goes into. It's to make sure memtable and index memtable are in sync.
      Returns:
      the newly created indexer or null if the index is not interested by the update (this could be because the index doesn't care about that particular partition, doesn't care about that type of transaction, ...).

    • deleteStaleEntry

      public void deleteStaleEntry(DecoratedKey indexKey, Clustering<?> indexClustering, DeletionTime deletion, WriteContext ctx)
      Specific to internal indexes, this is called by a searcher when it encounters a stale entry in the index
      Parameters:
      indexKey - the partition key in the index table
      indexClustering - the clustering in the index table
      deletion - deletion timestamp etc
      ctx - the write context under which to perform the deletion

    • indexCfsMetadata

      public static TableMetadata indexCfsMetadata(TableMetadata baseCfsMetadata, IndexMetadata indexMetadata)
      Construct the TableMetadata for an index table, the clustering columns in the index table vary dependent on the kind of the indexed value.
      Parameters:
      baseCfsMetadata -
      indexMetadata -
      Returns:

    • newIndex

      public static CassandraIndex newIndex(ColumnFamilyStore baseCfs, IndexMetadata indexMetadata)
      Factory method for new CassandraIndex instances
      Parameters:
      baseCfs -
      indexMetadata -
      Returns: