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org.apache.lens.server.api.query
Class AbstractQueryContext

java.lang.Object
  org.apache.lens.server.api.query.AbstractQueryContext

All Implemented Interfaces:

Serializable

Direct Known Subclasses:

ExplainQueryContext, PreparedQueryContext, QueryContext

public abstract class AbstractQueryContext
extends Object
implements Serializable

See Also:

Serialized Form

Nested Class Summary

static class

AbstractQueryContext.DriverEstimateRunnable Runnable to wrap estimate computation for a driver.

Field Summary

static org.apache.commons.logging.Log

LOG The Constant LOG

Method Summary

void	clearTransientStateAfterCompleted()
void	clearTransientStateAfterLaunch()
void	estimateCostForDrivers() Estimate cost for each driver and set in context
String	getDatabase() Returns database set while launching query
org.apache.hadoop.conf.Configuration	getDriverConf(LensDriver driver) Get driver conf
Map<LensDriver,AbstractQueryContext.DriverEstimateRunnable>	getDriverEstimateRunnables() Get runnables wrapping estimate computation, which could be processed offline
String	getDriverQuery(LensDriver driver) Get driver query
QueryCost	getDriverQueryCost(LensDriver driver) Get query cost for the driver
Exception	getDriverRewriteError(LensDriver driver) Get exception during rewrite.
String	getFinalDriverQuery(LensDriver driver)
org.apache.hadoop.hive.conf.HiveConf	getHiveConf() Gets HiveConf corresponding to query conf.
String	getLogHandle() Get handle of the query for logging purposes
LensDriver	getSelectedDriver() Wrapper method for convenience on driver context
org.apache.hadoop.conf.Configuration	getSelectedDriverConf() Wrapper method for convenience on driver context
String	getSelectedDriverQuery() Wrapper method for convenience on driver context
QueryCost	getSelectedDriverQueryCost() Get selected driver's cost
DriverQueryPlan	getSelectedDriverQueryPlan() Wrapper method for convenience on driver context
void	initTransientState()
void	setDriverQueries(Map<LensDriver,String> driverQueries) Set driver queries
void	setDriverQuery(LensDriver driver, String query) Set query for a given driver
void	setDriverRewriteError(LensDriver driver, Exception exp) Set exception during rewrite.
void	setFinalDriverQuery(LensDriver driver, String rewrittenQuery) Set final driver rewritten query for the driver.
void	setSelectedDriver(LensDriver driver) Wrapper method for convenience on driver context
void	setSelectedDriverQuery(String driverQuery) Sets the selected driver query for persistence and also in the driver context

Methods inherited from class java.lang.Object

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

Field Detail

LOG

public static final org.apache.commons.logging.Log LOG

The Constant LOG

Method Detail

initTransientState

public void initTransientState()

setDriverQueries

public void setDriverQueries(Map<LensDriver,String> driverQueries)
                      throws LensException

Set driver queries

Parameters:

driverQueries - Map of LensDriver to driver's query

Throws:

LensException

estimateCostForDrivers

public void estimateCostForDrivers()
                            throws LensException

Estimate cost for each driver and set in context

Throws:

LensException

getDriverEstimateRunnables

public Map<LensDriver,AbstractQueryContext.DriverEstimateRunnable> getDriverEstimateRunnables()
                                                                                       throws LensException

Get runnables wrapping estimate computation, which could be processed offline

Throws:

LensException

getSelectedDriverQuery

public String getSelectedDriverQuery()

Wrapper method for convenience on driver context

Returns:

the selected driver's query

getDriverQuery

public String getDriverQuery(LensDriver driver)

Get driver query

Parameters:

driver -

Returns:

query

getFinalDriverQuery

public String getFinalDriverQuery(LensDriver driver)

getDriverConf

public org.apache.hadoop.conf.Configuration getDriverConf(LensDriver driver)

Get driver conf

Parameters:

driver -

Returns:

Configuration

getDriverQueryCost

public QueryCost getDriverQueryCost(LensDriver driver)

Get query cost for the driver

Parameters:

driver -

Returns:

QueryCost

getSelectedDriverConf

public org.apache.hadoop.conf.Configuration getSelectedDriverConf()

Wrapper method for convenience on driver context

Returns:

the selected driver's conf

setSelectedDriverQuery

public void setSelectedDriverQuery(String driverQuery)

Sets the selected driver query for persistence and also in the driver context

Parameters:

driverQuery -

setSelectedDriver

public void setSelectedDriver(LensDriver driver)

Wrapper method for convenience on driver context

Parameters:

driver - Lens driver

getSelectedDriver

public LensDriver getSelectedDriver()

Wrapper method for convenience on driver context

Returns:

the selected driver

getSelectedDriverQueryPlan

public DriverQueryPlan getSelectedDriverQueryPlan()
                                           throws LensException

Wrapper method for convenience on driver context

Returns:

the selected driver

Throws:

LensException

getSelectedDriverQueryCost

public QueryCost getSelectedDriverQueryCost()
                                     throws LensException

Get selected driver's cost

Returns:

QueryCost

Throws:

LensException

setDriverRewriteError

public void setDriverRewriteError(LensDriver driver,
                                  Exception exp)

Set exception during rewrite.

Parameters:

driver -

exp -

getDriverRewriteError

public Exception getDriverRewriteError(LensDriver driver)

Get exception during rewrite.

Parameters:

driver -

Returns:

exp

getHiveConf

public org.apache.hadoop.hive.conf.HiveConf getHiveConf()

Gets HiveConf corresponding to query conf. Should be called judiciously, because constructing HiveConf from conf object is costly. The field is set to null after query completion. Should not be accessed after completion.

Returns:

setFinalDriverQuery

public void setFinalDriverQuery(LensDriver driver,
                                String rewrittenQuery)

Set final driver rewritten query for the driver.

Parameters:

driver -

rewrittenQuery -

setDriverQuery

public void setDriverQuery(LensDriver driver,
                           String query)

Set query for a given driver

Parameters:

driver - driver instance

query - query string

Throws:

LensException

getLogHandle

public String getLogHandle()

Get handle of the query for logging purposes

Returns:

getDatabase

public String getDatabase()

Returns database set while launching query

Returns:

clearTransientStateAfterLaunch

public void clearTransientStateAfterLaunch()

clearTransientStateAfterCompleted

public void clearTransientStateAfterCompleted()