Package org.apache.cassandra.cql3.statements

Class SelectStatement

java.lang.Object

org.apache.cassandra.cql3.statements.SelectStatement

All Implemented Interfaces:

CQLStatement, CQLStatement.SingleKeyspaceCqlStatement

@ThreadSafe
public class SelectStatement
extends java.lang.Object
implements CQLStatement.SingleKeyspaceCqlStatement

Encapsulates a completely parsed SELECT query, including the target column family, expression, result count, and ordering clause.

A number of public methods here are only used internally. However, many of these are made accessible for the benefit of custom QueryHandler implementations, so before reducing their accessibility due consideration should be given.

Note that select statements can be accessed by multiple threads, so we cannot rely on mutable attributes.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	SelectStatement.Parameters
static class	SelectStatement.RawStatement

Nested classes/interfaces inherited from interface org.apache.cassandra.cql3.CQLStatement

CQLStatement.Raw, CQLStatement.SingleKeyspaceCqlStatement

Field Summary

Fields

Modifier and Type	Field	Description
VariableSpecifications	bindVariables
static int	DEFAULT_PAGE_SIZE
SelectStatement.Parameters	parameters
TableMetadata	table
static java.lang.String	TOPK_AGGREGATION_ERROR
static java.lang.String	TOPK_CONSISTENCY_LEVEL_ERROR
static java.lang.String	TOPK_CONSISTENCY_LEVEL_WARNING
static java.lang.String	TOPK_LIMIT_ERROR
static java.lang.String	TOPK_PAGE_SIZE_WARNING
static java.lang.String	TOPK_PARTITION_LIMIT_ERROR

Constructor Summary

Constructors

Constructor

Description

SelectStatement(TableMetadata table, VariableSpecifications bindVariables, SelectStatement.Parameters parameters, Selection selection, StatementRestrictions restrictions, boolean isReversed, AggregationSpecification.Factory aggregationSpecFactory, org.apache.cassandra.cql3.statements.SelectStatement.ColumnComparator<java.util.List<java.nio.ByteBuffer>> orderingComparator, Term limit, Term perPartitionLimit)

Method Summary

Modifier and Type	Method	Description
void	authorize(ClientState state)	Perform any access verification necessary for the statement.
Slices	clusteringIndexFilterAsSlices()	Returns the slices fetched by this SELECT, assuming an internal call (no bound values in particular).
ResultMessage.Rows	execute(QueryState state, QueryOptions options, Dispatcher.RequestTime requestTime)	Execute the statement and return the resulting result or null if there is no result.
ResultMessage.Rows	executeInternal(QueryState state, QueryOptions options, long nowInSec, Dispatcher.RequestTime requestTime)
ResultMessage.Rows	executeLocally(QueryState state, QueryOptions options)	Variant of execute used for internal query against the system tables, and thus only query the local node.
java.util.Map<DecoratedKey,java.util.List<Row>>	executeRawInternal(QueryOptions options, ClientState state, long nowInSec)
AggregationSpecification	getAggregationSpec(QueryOptions options)
AuditLogContext	getAuditLogContext()	Provides the context needed for audit logging statements.
java.util.List<ColumnSpecification>	getBindVariables()	Returns all bind variables for the statement
static java.nio.ByteBuffer[]	getComponents(TableMetadata metadata, DecoratedKey dk)
java.lang.Iterable<Function>	getFunctions()	Return an Iterable over all of the functions (both native and user-defined) used by any component of the statement
int	getLimit(QueryOptions options)	Returns the limit specified by the user.
short[]	getPartitionKeyBindVariableIndexes()	Returns an array with the same length as the number of partition key columns for the table corresponding to table.
int	getPerPartitionLimit(QueryOptions options)	Returns the per partition limit specified by the user.
ReadQuery	getQuery(QueryOptions options, long nowInSec)
ReadQuery	getQuery(QueryOptions options, ClientState state, ColumnFilter columnFilter, long nowInSec, int userLimit, int perPartitionLimit, int pageSize, AggregationSpecification aggregationSpec)
ReadQuery	getQuery(QueryOptions options, ClientState state, ColumnFilter columnFilter, long nowInSec, DataLimits limit)
StatementRestrictions	getRestrictions()	May be used by custom QueryHandler implementations
ResultSet.ResultMetadata	getResultMetadata()
RowFilter	getRowFilter(QueryOptions options, ClientState state)	May be used by custom QueryHandler implementations
Selection	getSelection()	May be used by custom QueryHandler implementations
SinglePartitionReadCommand	internalReadForView(DecoratedKey key, long nowInSec)	Returns a read command that can be used internally to query all the rows queried by this SELECT for a give key (used for materialized views).
java.lang.String	keyspace()
Slices	makeSlices(QueryOptions options)
ResultSet	process(PartitionIterator partitions, long nowInSec, boolean unmask, ClientState state)
void	processPartition(RowIterator partition, QueryOptions options, ResultSetBuilder result, long nowInSec)
ColumnFilter	queriedColumns()	The columns to fetch internally for this SELECT statement (which can be more than the one selected by the user as it also include any restricted column in particular).
RowFilter	rowFilterForInternalCalls()	The RowFilter for this SELECT, assuming an internal call (no bound values in particular).
java.lang.String	table()
java.lang.String	toString()
void	validate(ClientState state)	Perform additional validation required by the statment.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.apache.cassandra.cql3.CQLStatement

hasConditions

Field Detail

DEFAULT_PAGE_SIZE

public static final int DEFAULT_PAGE_SIZE

See Also:

Constant Field Values

TOPK_CONSISTENCY_LEVEL_ERROR

public static final java.lang.String TOPK_CONSISTENCY_LEVEL_ERROR

See Also:

Constant Field Values

TOPK_LIMIT_ERROR

public static final java.lang.String TOPK_LIMIT_ERROR

See Also:

Constant Field Values

TOPK_PARTITION_LIMIT_ERROR

public static final java.lang.String TOPK_PARTITION_LIMIT_ERROR

See Also:

Constant Field Values

TOPK_AGGREGATION_ERROR

public static final java.lang.String TOPK_AGGREGATION_ERROR

See Also:

Constant Field Values

TOPK_CONSISTENCY_LEVEL_WARNING

public static final java.lang.String TOPK_CONSISTENCY_LEVEL_WARNING

See Also:

Constant Field Values

TOPK_PAGE_SIZE_WARNING

public static final java.lang.String TOPK_PAGE_SIZE_WARNING

See Also:

Constant Field Values

bindVariables

public final VariableSpecifications bindVariables

table

public final TableMetadata table

parameters

public final SelectStatement.Parameters parameters

Constructor Detail

SelectStatement

public SelectStatement(TableMetadata table,
                       VariableSpecifications bindVariables,
                       SelectStatement.Parameters parameters,
                       Selection selection,
                       StatementRestrictions restrictions,
                       boolean isReversed,
                       AggregationSpecification.Factory aggregationSpecFactory,
                       org.apache.cassandra.cql3.statements.SelectStatement.ColumnComparator<java.util.List<java.nio.ByteBuffer>> orderingComparator,
                       Term limit,
                       Term perPartitionLimit)

Method Detail

getBindVariables

public java.util.List<ColumnSpecification> getBindVariables()

Description copied from interface: CQLStatement

Returns all bind variables for the statement

Specified by:

getBindVariables in interface CQLStatement

getPartitionKeyBindVariableIndexes

public short[] getPartitionKeyBindVariableIndexes()

Description copied from interface: CQLStatement

Returns an array with the same length as the number of partition key columns for the table corresponding to table. Each short in the array represents the bind index of the marker that holds the value for that partition key column. If there are no bind markers for any of the partition key columns, null is returned.

Specified by:

getPartitionKeyBindVariableIndexes in interface CQLStatement

getFunctions

public java.lang.Iterable<Function> getFunctions()

Description copied from interface: CQLStatement

Return an Iterable over all of the functions (both native and user-defined) used by any component of the statement

Specified by:

getFunctions in interface CQLStatement

Returns:

functions all functions found (may contain duplicates)

queriedColumns

public ColumnFilter queriedColumns()

The columns to fetch internally for this SELECT statement (which can be more than the one selected by the user as it also include any restricted column in particular).

getResultMetadata

public ResultSet.ResultMetadata getResultMetadata()

authorize

public void authorize(ClientState state)
               throws InvalidRequestException,
                      UnauthorizedException

Description copied from interface: CQLStatement

Perform any access verification necessary for the statement.

Specified by:

authorize in interface CQLStatement

Parameters:

state - the current client state

Throws:

InvalidRequestException

UnauthorizedException

validate

public void validate(ClientState state)
              throws InvalidRequestException

Description copied from interface: CQLStatement

Perform additional validation required by the statment. To be overriden by subclasses if needed.

Specified by:

validate in interface CQLStatement

Parameters:

state - the current client state

Throws:

InvalidRequestException

execute

public ResultMessage.Rows execute(QueryState state,
                                  QueryOptions options,
                                  Dispatcher.RequestTime requestTime)

Description copied from interface: CQLStatement

Execute the statement and return the resulting result or null if there is no result.

Specified by:

execute in interface CQLStatement

Parameters:

state - the current query state

options - options for this query (consistency, variables, pageSize, ...)

requestTime - request enqueue / and start times;

getAggregationSpec

public AggregationSpecification getAggregationSpec(QueryOptions options)

getQuery

public ReadQuery getQuery(QueryOptions options,
                          long nowInSec)
                   throws RequestValidationException

Throws:

RequestValidationException

getQuery

public ReadQuery getQuery(QueryOptions options,
                          ClientState state,
                          ColumnFilter columnFilter,
                          long nowInSec,
                          int userLimit,
                          int perPartitionLimit,
                          int pageSize,
                          AggregationSpecification aggregationSpec)

getQuery

public ReadQuery getQuery(QueryOptions options,
                          ClientState state,
                          ColumnFilter columnFilter,
                          long nowInSec,
                          DataLimits limit)

getAuditLogContext

public AuditLogContext getAuditLogContext()

Description copied from interface: CQLStatement

Provides the context needed for audit logging statements.

Specified by:

getAuditLogContext in interface CQLStatement

executeLocally

public ResultMessage.Rows executeLocally(QueryState state,
                                         QueryOptions options)
                                  throws RequestExecutionException,
                                         RequestValidationException

Description copied from interface: CQLStatement

Variant of execute used for internal query against the system tables, and thus only query the local node.

Specified by:

executeLocally in interface CQLStatement

Parameters:

state - the current query state

Throws:

RequestExecutionException

RequestValidationException

executeInternal

public ResultMessage.Rows executeInternal(QueryState state,
                                          QueryOptions options,
                                          long nowInSec,
                                          Dispatcher.RequestTime requestTime)

executeRawInternal

public java.util.Map<DecoratedKey,java.util.List<Row>> executeRawInternal(QueryOptions options,
                                                                                ClientState state,
                                                                                long nowInSec)
                                                                         throws RequestExecutionException,
                                                                                RequestValidationException

Throws:

RequestExecutionException

RequestValidationException

process

public ResultSet process(PartitionIterator partitions,
                         long nowInSec,
                         boolean unmask,
                         ClientState state)
                  throws InvalidRequestException

Throws:

InvalidRequestException

keyspace

public java.lang.String keyspace()

Specified by:

keyspace in interface CQLStatement.SingleKeyspaceCqlStatement

table

public java.lang.String table()

getSelection

public Selection getSelection()

May be used by custom QueryHandler implementations

getRestrictions

public StatementRestrictions getRestrictions()

May be used by custom QueryHandler implementations

clusteringIndexFilterAsSlices

public Slices clusteringIndexFilterAsSlices()

Returns the slices fetched by this SELECT, assuming an internal call (no bound values in particular).

Note that if the SELECT intrinsically selects rows by names, we convert them into equivalent slices for the purpose of this method. This is used for MVs to restrict what needs to be read when we want to read everything that could be affected by a given view (and so, if the view SELECT statement has restrictions on the clustering columns, we can restrict what we read).

internalReadForView

public SinglePartitionReadCommand internalReadForView(DecoratedKey key,
                                                      long nowInSec)

Returns a read command that can be used internally to query all the rows queried by this SELECT for a give key (used for materialized views).

rowFilterForInternalCalls

public RowFilter rowFilterForInternalCalls()

The RowFilter for this SELECT, assuming an internal call (no bound values in particular).

makeSlices

public Slices makeSlices(QueryOptions options)
                  throws InvalidRequestException

Throws:

InvalidRequestException

getLimit

public int getLimit(QueryOptions options)

Returns the limit specified by the user. May be used by custom QueryHandler implementations

Returns:

the limit specified by the user or DataLimits.NO_LIMIT if no value as been specified.

getPerPartitionLimit

public int getPerPartitionLimit(QueryOptions options)

Returns the per partition limit specified by the user. May be used by custom QueryHandler implementations

Returns:

the per partition limit specified by the user or DataLimits.NO_LIMIT if no value as been specified.

getRowFilter

public RowFilter getRowFilter(QueryOptions options,
                              ClientState state)
                       throws InvalidRequestException

May be used by custom QueryHandler implementations

Throws:

InvalidRequestException

getComponents

public static java.nio.ByteBuffer[] getComponents(TableMetadata metadata,
                                                  DecoratedKey dk)

processPartition

public void processPartition(RowIterator partition,
                             QueryOptions options,
                             ResultSetBuilder result,
                             long nowInSec)
                      throws InvalidRequestException

Throws:

InvalidRequestException

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object