com.google.cloud.bigtable.data.v2.models

Class Query

java.lang.Object

com.google.cloud.bigtable.data.v2.models.Query

All Implemented Interfaces:

Serializable

public final class Query
extends Object
implements Serializable

A simple wrapper to construct a query for the ReadRows RPC.

See Also:

Serialized Form

Method Summary

Modifier and Type	Method and Description
static Query	create(String tableId) Constructs a new Query object for the specified table id.
boolean	equals(Object o)
Query	filter(Filters.Filter filter) Sets the filter to apply to each row.
static Query	fromProto(ReadRowsRequest request) Wraps the protobuf ReadRowsRequest.
Range.ByteStringRange	getBound() Get the minimal range that encloses all of the row keys and ranges in this Query.
int	hashCode()
Query	limit(long limit) Limits the number of rows that can be returned
Query	prefix(ByteString prefix)
Query	prefix(String prefix)
Query	range(ByteString start, ByteString end) Adds a range to be looked up.
Query	range(Range.ByteStringRange range) Adds a range to be looked up.
Query	range(String start, String end) Adds a range to be looked up.
Query	rowKey(ByteString key) Adds a key to looked up
Query	rowKey(String key) Adds a key to looked up
List<Query>	shard(List<KeyOffset> sampledRowKeys) Split this query into multiple queries that can be evenly distributed across Bigtable nodes and be run in parallel.
List<Query>	shard(SortedSet<ByteString> splitPoints) Split this query into multiple queries that logically combine into this query.
ReadRowsRequest	toProto(com.google.cloud.bigtable.data.v2.internal.RequestContext requestContext) Creates the request protobuf.
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Method Detail

create

public static Query create(String tableId)

Constructs a new Query object for the specified table id. The table id will be combined with the instance name specified in the BigtableDataSettings.

rowKey

public Query rowKey(String key)

Adds a key to looked up

rowKey

public Query rowKey(ByteString key)

Adds a key to looked up

prefix

public Query prefix(ByteString prefix)

prefix

public Query prefix(String prefix)

range

public Query range(String start,
                   String end)

Adds a range to be looked up.

Parameters:

start - The beginning of the range (inclusive). Can be null to represent negative infinity.

end - The end of the range (exclusive). Can be null to represent positive infinity.

range

public Query range(ByteString start,
                   ByteString end)

Adds a range to be looked up.

Parameters:

start - The beginning of the range (inclusive). Can be null to represent negative infinity.

end - The end of the range (exclusive). Can be null to represent positive infinity.

range

public Query range(Range.ByteStringRange range)

Adds a range to be looked up.

filter

public Query filter(Filters.Filter filter)

Sets the filter to apply to each row. Only one filter can be set at a time. To use multiple filters, please use Filters.interleave() or Filters.chain().

limit

public Query limit(long limit)

Limits the number of rows that can be returned

shard

public List<Query> shard(List<KeyOffset> sampledRowKeys)

Split this query into multiple queries that can be evenly distributed across Bigtable nodes and be run in parallel. This method takes the results from BigtableDataClient.sampleRowKeysAsync(String) to divide this query into a set of disjoint queries that logically combine into form this query.

Expected Usage:

 List<KeyOffset> keyOffsets = dataClient.sampleRowKeysAsync("my-table").get();
 List<Query> queryShards = myQuery.shard(keyOffsets);
 List<ApiFuture<List<Row>>> futures = new ArrayList();
 for (Query subQuery : queryShards) {
   futures.add(dataClient.readRowsCallable().all().futureCall(subQuery));
 }
 List<List<Row>> results = ApiFutures.allAsList(futures).get();
 

shard

public List<Query> shard(SortedSet<ByteString> splitPoints)

Split this query into multiple queries that logically combine into this query. This is intended to be used by map reduce style frameworks like Beam to split a query across multiple workers.

Expected Usage:

 List<ByteString> splitPoints = ...;
 List<Query> queryShards = myQuery.shard(splitPoints);
 List<ApiFuture<List<Row>>> futures = new ArrayList();
 for (Query subQuery : queryShards) {
   futures.add(dataClient.readRowsCallable().all().futureCall(subQuery));
 }
 List<List<Row>> results = ApiFutures.allAsList(futures).get();
 

getBound

public Range.ByteStringRange getBound()

Get the minimal range that encloses all of the row keys and ranges in this Query.

toProto

@InternalApi
public ReadRowsRequest toProto(com.google.cloud.bigtable.data.v2.internal.RequestContext requestContext)

Creates the request protobuf. This method is considered an internal implementation detail and not meant to be used by applications.

fromProto

public static Query fromProto(@Nonnull
                              ReadRowsRequest request)

Wraps the protobuf ReadRowsRequest.

WARNING: Please note that the project id & instance id in the table name will be overwritten by the configuration in the BigtableDataClient.

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object