Scan#

Interface#

class TableScan#

A scanner interface for reading table’s meta and create a plan.

Public Functions

virtual ~TableScan() = default#

virtual Result<std::shared_ptr<Plan>> CreatePlan() = 0#

Create a scan plan.

Returns:: A Result containing a shared pointer to the created Plan or an error status.

Public Static Functions

static Result<std::unique_ptr<TableScan>> Create(std::unique_ptr<ScanContext> context)#

Create an instance of TableScan.

Parameters:: context – A unique pointer to the ScanContext used for scan operations.
Returns:: A Result containing a unique pointer to the TableScan instance.

class ScanContextBuilder#

ScanContextBuilder used to build a ScanContext, has input validation.

Public Functions

explicit ScanContextBuilder(const std::string &path)#

Constructs a ScanContextBuilder with required parameters.

Parameters:: path – The root path of the table.

~ScanContextBuilder()#

ScanContextBuilder &SetLimit(int32_t limit)#: If limit is not set, it defaults to unlimited.

ScanContextBuilder &SetBucketFilter(int32_t bucket_filter)#: Set a bucket filter to scan only specific bucket.

ScanContextBuilder &SetPartitionFilter(const std::vector<std::map<std::string, std::string>> &partition_filters)#: partition_filters in vector is supposed to be OR, filter in map is supposed to be AND, e.g., partition_filters is {{k1=1,k2=10}, {k1=2,k2=20}} => OR(AND(k1=1,k2=10), AND(k1=2,k2=20))

ScanContextBuilder &SetPredicate(const std::shared_ptr<Predicate> &predicate)#: Set a predicate for filtering data.

ScanContextBuilder &SetRowRanges(const std::vector<Range> &row_ranges)#

Specify the row id ranges for scan.

This is usually used to read specific rows in data-evolution mode. File ranges that do not have any intersection with range_ids will be filtered. If not set, all rows are returned

ScanContextBuilder &AddOption(const std::string &key, const std::string &value)#: The options added or set in ScanContextBuilder have high priority and will be merged with the options in table schema.

ScanContextBuilder &SetOptions(const std::map<std::string, std::string> &options)#

Set a configuration options map to set some option entries which are not defined in the table schema or whose values you want to overwrite.

Note

The options map will clear the options added by AddOption() before.

Parameters:: options – The configuration options map.
Returns:: Reference to this builder for method chaining.

ScanContextBuilder &WithStreamingMode(bool is_streaming_mode)#: Set whether the scan is in streaming mode.

Note

if not set, is_streaming_mode = false

ScanContextBuilder &WithMemoryPool(const std::shared_ptr<MemoryPool> &memory_pool)#

Set custom memory pool for memory management.

Note

if not set, memory_pool is default pool

Parameters:: memory_pool – The memory pool to use.
Returns:: Reference to this builder for method chaining.

ScanContextBuilder &WithExecutor(const std::shared_ptr<Executor> &executor)#

Set custom executor for task execution.

Note

if not set, executor is default executor

Parameters:: executor – The executor to use.
Returns:: Reference to this builder for method chaining.

Result<std::unique_ptr<ScanContext>> Finish()#

Build and return a ScanContext instance with input validation.

Returns:: Result containing the constructed ScanContext or an error status.

class ScanContext#

ScanContext is some configuration for table scan operations.

Please do not use this class directly, use ScanContextBuilder to build a ScanContext which has input validation.