public final class Query implements Serializable
A simple wrapper to construct a query for the ReadRows RPC.
Static Methods
create(String tableId)
public static Query create(String tableId)
| Parameter |
|---|
| Name | Description |
tableId | String
|
| Returns |
|---|
| Type | Description |
Query | |
fromProto(ReadRowsRequest request)
public static Query fromProto(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.
| Parameter |
|---|
| Name | Description |
request | com.google.bigtable.v2.ReadRowsRequest
|
| Returns |
|---|
| Type | Description |
Query | |
Methods
clone()
| Returns |
|---|
| Type | Description |
Query | |
Overrides
createPaginator(int pageSize)
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));
| Parameter |
|---|
| Name | Description |
pageSize | int
|
equals(Object o)
public boolean equals(Object o)
| Parameter |
|---|
| Name | Description |
o | Object
|
Overrides
filter(Filters.Filter filter)
public Query filter(Filters.Filter filter)
| Returns |
|---|
| Type | Description |
Query | |
getBound()
public Range.ByteStringRange getBound()
Get the minimal range that encloses all of the row keys and ranges in this Query.
hashCode()
| Returns |
|---|
| Type | Description |
int | |
Overrides
limit(long limit)
public Query limit(long limit)
Limits the number of rows that can be returned
| Parameter |
|---|
| Name | Description |
limit | long
|
| Returns |
|---|
| Type | Description |
Query | |
prefix(ByteString prefix)
public Query prefix(ByteString prefix)
| Returns |
|---|
| Type | Description |
Query | |
prefix(String prefix)
public Query prefix(String prefix)
| Parameter |
|---|
| Name | Description |
prefix | String
|
| Returns |
|---|
| Type | Description |
Query | |
range(Range.ByteStringRange range)
public Query range(Range.ByteStringRange range)
Adds a range to be looked up.
| Returns |
|---|
| Type | Description |
Query | |
range(ByteString start, ByteString end)
public Query range(ByteString start, ByteString end)
Adds a range to be looked up.
| Parameters |
|---|
| Name | Description |
start | ByteString
The beginning of the range (inclusive). Can be null to represent negative
infinity.
|
end | ByteString
The end of the range (exclusive). Can be null to represent positive infinity.
|
| Returns |
|---|
| Type | Description |
Query | |
range(String start, String end)
public Query range(String start, String end)
Adds a range to be looked up.
| Parameters |
|---|
| Name | Description |
start | String
The beginning of the range (inclusive). Can be null to represent negative
infinity.
|
end | String
The end of the range (exclusive). Can be null to represent positive infinity.
|
| Returns |
|---|
| Type | Description |
Query | |
reversed(boolean enable)
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)
| Parameter |
|---|
| Name | Description |
enable | boolean
|
| Returns |
|---|
| Type | Description |
Query | |
rowKey(ByteString key)
public Query rowKey(ByteString key)
| Returns |
|---|
| Type | Description |
Query | |
rowKey(String key)
public Query rowKey(String key)
| Parameter |
|---|
| Name | Description |
key | String
|
| Returns |
|---|
| Type | Description |
Query | |
shard(List<KeyOffset> sampledRowKeys)
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 com.google.cloud.bigtable.data.v2.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
shard(SortedSet<ByteString> splitPoints)
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
toProto(RequestContext requestContext)
public ReadRowsRequest toProto(RequestContext requestContext)
Creates the request protobuf. This method is considered an internal implementation detail and
not meant to be used by applications.
| Parameter |
|---|
| Name | Description |
requestContext | com.google.cloud.bigtable.data.v2.internal.RequestContext
|
| Returns |
|---|
| Type | Description |
com.google.bigtable.v2.ReadRowsRequest | |
toString()
Overrides
