Builds scan tokens for a table. More...

#include <client.h>

Public Member Functions
	KuduScanTokenBuilder (KuduTable *table)
Status	SetProjectedColumnNames (const std::vector< std::string > &col_names) WARN_UNUSED_RESULT
Status	SetProjectedColumnIndexes (const std::vector< int > &col_indexes) WARN_UNUSED_RESULT
Status	AddConjunctPredicate (KuduPredicate *pred) WARN_UNUSED_RESULT
Status	AddLowerBound (const KuduPartialRow &key) WARN_UNUSED_RESULT
Status	AddUpperBound (const KuduPartialRow &key) WARN_UNUSED_RESULT
Status	SetCacheBlocks (bool cache_blocks) WARN_UNUSED_RESULT
Status	SetBatchSizeBytes (uint32_t batch_size) WARN_UNUSED_RESULT
Status	SetSelection (KuduClient::ReplicaSelection selection) WARN_UNUSED_RESULT
Status	SetReadMode (KuduScanner::ReadMode read_mode) WARN_UNUSED_RESULT
Status	SetFaultTolerant () WARN_UNUSED_RESULT
Status	SetSnapshotMicros (uint64_t snapshot_timestamp_micros) WARN_UNUSED_RESULT
Status	SetSnapshotRaw (uint64_t snapshot_timestamp) WARN_UNUSED_RESULT
Status	SetTimeoutMillis (int millis) WARN_UNUSED_RESULT
Status	IncludeTableMetadata (bool include_metadata) WARN_UNUSED_RESULT
Status	IncludeTabletMetadata (bool include_metadata) WARN_UNUSED_RESULT
Status	SetQueryId (const std::string &query_id)
void	SetSplitSizeBytes (uint64_t split_size_bytes)
Status	Build (std::vector< KuduScanToken * > *tokens) WARN_UNUSED_RESULT

Detailed Description

Builds scan tokens for a table.

Note: This class is not thread-safe.

Constructor & Destructor Documentation

◆ KuduScanTokenBuilder()

kudu::client::KuduScanTokenBuilder::KuduScanTokenBuilder ( KuduTable * table )

explicit

Construct an instance of the class.

Parameters

[in] table The table the tokens should scan. The given object must remain valid for the lifetime of the builder, and the tokens which it builds.

Member Function Documentation

◆ AddConjunctPredicate()

Status kudu::client::KuduScanTokenBuilder::AddConjunctPredicate ( KuduPredicate * pred )

Add a predicate for the scan.

Parameters

[in] pred Predicate to set. The KuduScanTokenBuilder instance takes ownership of the parameter even if a bad Status is returned. Multiple calls of this method make the specified set of predicates work in conjunction, i.e. all predicates must be true for a row to be returned.

Returns: Operation result status.

◆ AddLowerBound()

Status kudu::client::KuduScanTokenBuilder::AddLowerBound ( const KuduPartialRow & key )

Add a lower bound (inclusive) primary key for the scan.

If any bound is already added, this bound is intersected with that one.

Parameters

[in] key Lower bound primary key to add. The KuduScanTokenBuilder instance does not take ownership of the parameter.

Returns: Operation result status.

◆ AddUpperBound()

Status kudu::client::KuduScanTokenBuilder::AddUpperBound ( const KuduPartialRow & key )

Add an upper bound (exclusive) primary key.

If any bound is already added, this bound is intersected with that one.

Parameters

[in] key Upper bound primary key to add. The KuduScanTokenBuilder instance does not take ownership of the parameter.

Returns: Operation result status.

◆ Build()

Status kudu::client::KuduScanTokenBuilder::Build ( std::vector< KuduScanToken * > * tokens )

Build the set of scan tokens.

The builder may be reused after this call.

Parameters

[out] tokens Result set of tokens. The caller takes ownership of the container elements.

Returns: Operation result status.

◆ IncludeTableMetadata()

Status kudu::client::KuduScanTokenBuilder::IncludeTableMetadata ( bool include_metadata )

If the table metadata is included on the scan token a GetTableSchema RPC call to the master can be avoided when deserializing each scan token into a scanner.

Parameters

[in] include_metadata true, if table metadata should be included.

Returns: Operation result status.

◆ IncludeTabletMetadata()

Status kudu::client::KuduScanTokenBuilder::IncludeTabletMetadata ( bool include_metadata )

If the tablet metadata is included on the scan token a GetTableLocations RPC call to the master can be avoided when scanning with a scanner constructed from a scan token.

Parameters

[in] include_metadata true, if table metadata should be included.

Returns: Operation result status.

◆ SetBatchSizeBytes()

Status kudu::client::KuduScanTokenBuilder::SetBatchSizeBytes ( uint32_t batch_size )

Set the hint for the size of the next batch in bytes.

Parameters

[in] batch_size Batch size to set (in bytes). If set to 0, the first call to the tablet server won't return data.

Returns: Operation result status.

◆ SetCacheBlocks()

Status kudu::client::KuduScanTokenBuilder::SetCacheBlocks ( bool cache_blocks )

Set the block caching policy.

Parameters

[in] cache_blocks If true, scanned data blocks will be cached in memory and made available for future scans. Default is true.

Returns: Operation result status.

◆ SetFaultTolerant()

Status kudu::client::KuduScanTokenBuilder::SetFaultTolerant ( )

Make scans resumable at another tablet server if current server fails.

Scans are by default non fault-tolerant, and scans will fail if scanning an individual tablet fails (for example, if a tablet server crashes in the middle of a tablet scan). If this method is called, scans will be resumed at another tablet server in the case of failure.

Fault-tolerant scans typically have lower throughput than non fault-tolerant scans. Fault tolerant scans use READ_AT_SNAPSHOT mode: if no snapshot timestamp is provided, the server will pick one.

Returns: Operation result status.

◆ SetProjectedColumnIndexes()

Status kudu::client::KuduScanTokenBuilder::SetProjectedColumnIndexes ( const std::vector< int > & col_indexes )

Set the column projection by passing the column indexes to read.

Set the column projection used for this scanner by passing the column indices to read. A call to this method overrides any previous call to SetProjectedColumnNames() or SetProjectedColumnIndexes().

Parameters

[in] col_indexes Column indices for the projection.

Returns: Operation result status.

◆ SetProjectedColumnNames()

Status kudu::client::KuduScanTokenBuilder::SetProjectedColumnNames ( const std::vector< std::string > & col_names )

Set the column projection by passing the column names to read.

Set the column projection used for this scanner by passing the column names to read. A call of this method overrides any previous call to SetProjectedColumnNames() or SetProjectedColumnIndexes().

Parameters

[in] col_names Column names for the projection.

Returns: Operation result status.

◆ SetQueryId()

Status kudu::client::KuduScanTokenBuilder::SetQueryId ( const std::string & query_id )

Set a query id for the scan to trace the whole process. Query id is set by the user or generated automatically. It is used to trace the whole query process for for troubleshooting and debugging.

Parameters

[in] query_id A query id to identify a query.

Returns: Operation result status.

◆ SetReadMode()

Status kudu::client::KuduScanTokenBuilder::SetReadMode ( KuduScanner::ReadMode read_mode )

Set the ReadMode. Default is READ_LATEST.

Parameters

[in] read_mode Read mode to set.

Returns: Operation result status.

◆ SetSelection()

Status kudu::client::KuduScanTokenBuilder::SetSelection ( KuduClient::ReplicaSelection selection )

Set the replica selection policy while scanning.

Parameters

[in] selection Selection policy to set.

Returns: Operation result status.

Todo: Kill this in favor of a consistency-level-based API.

◆ SetSnapshotMicros()

Status kudu::client::KuduScanTokenBuilder::SetSnapshotMicros ( uint64_t snapshot_timestamp_micros )

Set snapshot timestamp for scans in READ_AT_SNAPSHOT mode.

Parameters

[in] snapshot_timestamp_micros Timestamp to set in in microseconds since the Epoch.

Returns: Operation result status.

◆ SetSnapshotRaw()

Status kudu::client::KuduScanTokenBuilder::SetSnapshotRaw ( uint64_t snapshot_timestamp )

Set snapshot timestamp for scans in READ_AT_SNAPSHOT mode (raw).

Note: This method is experimental and will either disappear or change in a future release.

Parameters

[in] snapshot_timestamp Timestamp to set in raw encoded form (i.e. as returned by a previous call to a server).

Returns: Operation result status.

◆ SetSplitSizeBytes()

void kudu::client::KuduScanTokenBuilder::SetSplitSizeBytes ( uint64_t split_size_bytes )

Set approximate data size (in bytes) for each key range that a single scan token is built for.

Parameters

[in] split_size_bytes The approximate target size of the data to be retrieved per scan token. If set to 0 (and that's the default, unless explicitly set by calling this method), the key ranges of the scan tokens to be produced are determined by the table's partition schema, so a single token is built per single tablet. Also see KuduScanToken#setSplitSizeBytes in the Java client.

◆ SetTimeoutMillis()

Status kudu::client::KuduScanTokenBuilder::SetTimeoutMillis ( int millis )

Set the maximum time that Open() and NextBatch() are allowed to take.

Parameters

[in] millis Timeout to set (in milliseconds). Must be greater than 0.

Returns: Operation result status.

The documentation for this class was generated from the following file:

include/kudu/client/client.h

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ KuduScanTokenBuilder()

Member Function Documentation

◆ AddConjunctPredicate()

◆ AddLowerBound()

◆ AddUpperBound()

◆ Build()

◆ IncludeTableMetadata()

◆ IncludeTabletMetadata()

◆ SetBatchSizeBytes()

◆ SetCacheBlocks()

◆ SetFaultTolerant()

◆ SetProjectedColumnIndexes()

◆ SetProjectedColumnNames()

◆ SetQueryId()

◆ SetReadMode()

◆ SetSelection()

◆ SetSnapshotMicros()

◆ SetSnapshotRaw()

◆ SetSplitSizeBytes()

◆ SetTimeoutMillis()