org.apache.drill.exec.planner.sql

Class SchemaUtilites

java.lang.Object

org.apache.drill.exec.planner.sql.SchemaUtilites

public class SchemaUtilites
extends Object

Field Summary

Fields

Modifier and Type	Field and Description
static com.google.common.base.Joiner	SCHEMA_PATH_JOINER

Constructor Summary

Constructors

Constructor and Description
SchemaUtilites()

Method Summary

Methods

Modifier and Type	Method and Description
static org.apache.calcite.schema.SchemaPlus	findSchema(org.apache.calcite.schema.SchemaPlus defaultSchema, List<String> schemaPath) Search and return schema with given schemaPath.
static org.apache.calcite.schema.SchemaPlus	findSchema(org.apache.calcite.schema.SchemaPlus defaultSchema, String schemaPath) Same utility as findSchema(SchemaPlus, List) except the search schema path given here is complete path instead of list.
static String	getPrefixSchemaPath(String defaultSchema, String schemaPath, boolean isCaseSensitive) Utility function to get the commonPrefix schema between two supplied schemas.
static String	getSchemaPath(List<String> schemaPath) Utility method to get the schema path for given list of schema path.
static String	getSchemaPath(org.apache.calcite.schema.SchemaPlus schema) Utility method to get the schema path for given schema instance.
static List<String>	getSchemaPathAsList(org.apache.calcite.schema.SchemaPlus schema) Utility method to get the schema path as list for given schema instance.
static AbstractSchema	getTemporaryWorkspace(org.apache.calcite.schema.SchemaPlus defaultSchema, DrillConfig config) Looks in schema tree for default temporary workspace instance.
static boolean	isRootSchema(org.apache.calcite.schema.SchemaPlus schema)
static boolean	isTemporaryWorkspace(String schemaPath, DrillConfig config) Checks that passed schema path is the same as temporary workspace path.
static AbstractSchema	resolveToMutableDrillSchema(org.apache.calcite.schema.SchemaPlus defaultSchema, List<String> schemaPath) Given reference to default schema in schema tree, search for schema with given schemaPath.
static WorkspaceSchemaFactory.WorkspaceSchema	resolveToValidTemporaryWorkspace(AbstractSchema schema, DrillConfig config) Makes sure that passed workspace exists, is default temporary workspace, mutable and file-based (instance of WorkspaceSchemaFactory.WorkspaceSchema).
static void	throwSchemaNotFoundException(org.apache.calcite.schema.SchemaPlus defaultSchema, List<String> givenSchemaPath) Utility method to throw UserException with context information
static void	throwSchemaNotFoundException(org.apache.calcite.schema.SchemaPlus defaultSchema, String givenSchemaPath) Utility method to throw UserException with context information
static AbstractSchema	unwrapAsDrillSchemaInstance(org.apache.calcite.schema.SchemaPlus schemaPlus) Unwrap given SchemaPlus instance as Drill schema instance (AbstractSchema).

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

SCHEMA_PATH_JOINER

public static final com.google.common.base.Joiner SCHEMA_PATH_JOINER

Constructor Detail

SchemaUtilites

public SchemaUtilites()

Method Detail

findSchema

public static org.apache.calcite.schema.SchemaPlus findSchema(org.apache.calcite.schema.SchemaPlus defaultSchema,
                                              List<String> schemaPath)

Search and return schema with given schemaPath. First search in schema tree starting from defaultSchema, if not found search starting from rootSchema. Root schema tree is derived from the defaultSchema reference.

Parameters:

defaultSchema - Reference to the default schema in complete schema tree.

schemaPath - Schema path to search.

Returns:

SchemaPlus object.

findSchema

public static org.apache.calcite.schema.SchemaPlus findSchema(org.apache.calcite.schema.SchemaPlus defaultSchema,
                                              String schemaPath)

Same utility as findSchema(SchemaPlus, List) except the search schema path given here is complete path instead of list. Use "." separator to divided the schema into nested schema names.

Parameters:

defaultSchema - default schema

schemaPath - current schema path

Returns:

found schema path

getPrefixSchemaPath

public static String getPrefixSchemaPath(String defaultSchema,
                         String schemaPath,
                         boolean isCaseSensitive)

Utility function to get the commonPrefix schema between two supplied schemas. Eg: if the defaultSchema: dfs and the schemaPath is dfs.tmp.`cicks.json` then this function returns dfs if (caseSensitive is not true otherwise it returns empty string.

Parameters:

defaultSchema - default schema

schemaPath - current schema path

isCaseSensitive - true if caseSensitive comparision is required.

Returns:

common prefix schemaPath

isRootSchema

public static boolean isRootSchema(org.apache.calcite.schema.SchemaPlus schema)

Parameters:

schema - current schema

Returns:

true if the given schema is root schema. False otherwise.

unwrapAsDrillSchemaInstance

public static AbstractSchema unwrapAsDrillSchemaInstance(org.apache.calcite.schema.SchemaPlus schemaPlus)

Unwrap given SchemaPlus instance as Drill schema instance (AbstractSchema). Once unwrapped, return default schema from AbstractSchema. If the given schema is not an instance of AbstractSchema a UserException is thrown.

getSchemaPath

public static String getSchemaPath(org.apache.calcite.schema.SchemaPlus schema)

Utility method to get the schema path for given schema instance.

getSchemaPath

public static String getSchemaPath(List<String> schemaPath)

Utility method to get the schema path for given list of schema path.

getSchemaPathAsList

public static List<String> getSchemaPathAsList(org.apache.calcite.schema.SchemaPlus schema)

Utility method to get the schema path as list for given schema instance.

throwSchemaNotFoundException

public static void throwSchemaNotFoundException(org.apache.calcite.schema.SchemaPlus defaultSchema,
                                String givenSchemaPath)

Utility method to throw UserException with context information

throwSchemaNotFoundException

public static void throwSchemaNotFoundException(org.apache.calcite.schema.SchemaPlus defaultSchema,
                                List<String> givenSchemaPath)

Utility method to throw UserException with context information

resolveToMutableDrillSchema

public static AbstractSchema resolveToMutableDrillSchema(org.apache.calcite.schema.SchemaPlus defaultSchema,
                                         List<String> schemaPath)

Given reference to default schema in schema tree, search for schema with given schemaPath. Once a schema is found resolve it into a mutable AbstractDrillSchema instance. A UserException is throws when:

No schema for given schemaPath is found. Schema found for given schemaPath is a root schema. Resolved schema is not a mutable schema.

Parameters:

defaultSchema - default schema

schemaPath - current schema path

Returns:

mutable schema, exception otherwise

getTemporaryWorkspace

public static AbstractSchema getTemporaryWorkspace(org.apache.calcite.schema.SchemaPlus defaultSchema,
                                   DrillConfig config)

Looks in schema tree for default temporary workspace instance.

Parameters:

defaultSchema - default schema

config - drill config

Returns:

default temporary workspace, null if workspace was not found

isTemporaryWorkspace

public static boolean isTemporaryWorkspace(String schemaPath,
                           DrillConfig config)

Checks that passed schema path is the same as temporary workspace path. Check is case-sensitive.

Parameters:

schemaPath - schema path

config - drill config

Returns:

true is schema path corresponds to temporary workspace, false otherwise

resolveToValidTemporaryWorkspace

public static WorkspaceSchemaFactory.WorkspaceSchema resolveToValidTemporaryWorkspace(AbstractSchema schema,
                                                                      DrillConfig config)

Makes sure that passed workspace exists, is default temporary workspace, mutable and file-based (instance of WorkspaceSchemaFactory.WorkspaceSchema).

Parameters:

schema - drill schema

config - drill config

Returns:

mutable & file-based workspace instance, otherwise throws validation error