org.apache.drill.exec.store

Interface StoragePlugin

All Superinterfaces:

AutoCloseable, SchemaFactory

All Known Implementing Classes:

AbstractStoragePlugin, FileSystemPlugin, InfoSchemaStoragePlugin, MockBreakageStorage, MockStorageEngine, SystemTablePlugin

public interface StoragePlugin
extends SchemaFactory, AutoCloseable

Interface for all implementations of the storage plugins. Different implementations of the storage formats will implement methods that indicate if Drill can write or read its tables from that format, if there are optimizer rules specific for the format, getting a storage config. etc.

Field Summary

Fields inherited from interface org.apache.drill.exec.store.SchemaFactory

logger

Method Summary

Methods

Modifier and Type	Method and Description
StoragePluginConfig	getConfig() Method returns a Jackson serializable object that extends a StoragePluginConfig
Set<? extends org.apache.calcite.plan.RelOptRule>	getOptimizerRules(OptimizerRulesContext optimizerContext) Deprecated.
AbstractGroupScan	getPhysicalScan(String userName, JSONOptions selection) Get the physical scan operator for the particular GroupScan (read) node.
AbstractGroupScan	getPhysicalScan(String userName, JSONOptions selection, List<SchemaPath> columns) Get the physical scan operator for the particular GroupScan (read) node.
void	start() Initialize the storage plugin.
boolean	supportsRead() Indicates if Drill can read the table from this format.
boolean	supportsWrite() Indicates if Drill can write a table to this format (e.g.

Methods inherited from interface org.apache.drill.exec.store.SchemaFactory

registerSchemas

Methods inherited from interface java.lang.AutoCloseable

close

Method Detail

supportsRead

boolean supportsRead()

Indicates if Drill can read the table from this format.

supportsWrite

boolean supportsWrite()

Indicates if Drill can write a table to this format (e.g. as JSON, csv, etc.).

getOptimizerRules

@Deprecated
Set<? extends org.apache.calcite.plan.RelOptRule> getOptimizerRules(OptimizerRulesContext optimizerContext)

Deprecated.

An implementation of this method will return one or more specialized rules that Drill query optimizer can leverage in physical space. Otherwise, it should return an empty set.

Returns:

an empty set or a set of plugin specific physical optimizer rules.

getPhysicalScan

AbstractGroupScan getPhysicalScan(String userName,
                                JSONOptions selection)
                                  throws IOException

Get the physical scan operator for the particular GroupScan (read) node.

Parameters:

userName - User whom to impersonate when when reading the contents as part of Scan.

selection - The configured storage engine specific selection.

Returns:

Throws:

IOException

getPhysicalScan

AbstractGroupScan getPhysicalScan(String userName,
                                JSONOptions selection,
                                List<SchemaPath> columns)
                                  throws IOException

Get the physical scan operator for the particular GroupScan (read) node.

Parameters:

userName - User whom to impersonate when when reading the contents as part of Scan.

selection - The configured storage engine specific selection.

columns - (optional) The list of column names to scan from the data source.

Returns:

Throws:

IOException

getConfig

StoragePluginConfig getConfig()

Method returns a Jackson serializable object that extends a StoragePluginConfig

Returns:

an extension of StoragePluginConfig

start

void start()
           throws IOException

Initialize the storage plugin. The storage plugin will not be used until this method is called.

Throws:

IOException