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

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Query.QueryPaginator A Query Paginator that will split a query into small chunks.

Method Summary

Modifier and Type	Method and Description
Query	clone()
static Query	create(String tableId) Deprecated. Please use create(TargetId) instead.
static Query	create(TargetId targetId) Constructs a new Query object for the given target with targetId.
Query.QueryPaginator	createPaginator(int pageSize) Create a query paginator that'll split the query into smaller chunks.
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.
TargetId	getTargetId()
int	hashCode()
Query	limit(long limit) Limits the number of rows that can be returned
Query	prefix(com.google.protobuf.ByteString prefix)
Query	prefix(String prefix)
Query	range(com.google.protobuf.ByteString start, com.google.protobuf.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	reversed(boolean enable) Return rows in reverse order.
Query	rowKey(com.google.protobuf.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<com.google.protobuf.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.
SessionReadRowRequest	toSessionPointProto()
String	toString()

Methods inherited from class java.lang.Object

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

Method Detail

create

@Deprecated
public static Query create(String tableId)

Deprecated. Please use create(TargetId) instead.

create

public static Query create(TargetId targetId)

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

See Also:

AuthorizedViewId, MaterializedViewId, TableId

rowKey

public Query rowKey(String key)

Adds a key to looked up

rowKey

public Query rowKey(com.google.protobuf.ByteString key)

Adds a key to looked up

prefix

public Query prefix(com.google.protobuf.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(com.google.protobuf.ByteString start,
                   com.google.protobuf.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

reversed

public Query reversed(boolean enable)

Return rows in reverse order.

The row will be streamed in reverse lexiographic order of the keys. The row key ranges are still expected to be oriented the same way as forwards. ie [a,c] where a <= c. The row content will remain unchanged from the ordering forward scans. This is particularly useful to get the last N records before a key:

 query
   .range(ByteStringRange.unbounded().endOpen("key"))
   .limit(10)
   .reversed(true)
 

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<com.google.protobuf.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();
 

createPaginator

@BetaApi(value="This surface is stable yet it might be removed in the future.")
public Query.QueryPaginator createPaginator(int pageSize)

Create a query paginator that'll split the query into smaller chunks.

Example usage:

 Query query = Query.create(...).range("a", "z");
 Query.QueryPaginator paginator = query.createQueryPaginator(100);
 ByteString lastSeenRowKey = ByteString.EMPTY;
 do {
     List<Row> rows = client.readRowsCallable().all().call(paginator.getNextQuery());
     for (Row row : rows) {
        // do some processing
        lastSeenRow = row;
     }
 } while (paginator.advance(lastSeenRowKey));
 

getBound

public Range.ByteStringRange getBound()

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

getTargetId

@InternalApi
public TargetId getTargetId()

toSessionPointProto

@InternalApi
public SessionReadRowRequest toSessionPointProto()

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.

clone

public Query clone()

Overrides:

clone in class Object

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