org.apache.hadoop.hive.metastore

Class AggregateStatsCache

java.lang.Object

org.apache.hadoop.hive.metastore.AggregateStatsCache

public class AggregateStatsCache
extends Object

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	AggregateStatsCache.AggrColStats

Method Summary

Methods

Modifier and Type	Method and Description
void	add(String dbName, String tblName, String colName, long numPartsCached, ColumnStatisticsObj colStats, BloomFilter bloomFilter) Add a new node to the cache; may trigger the cleaner thread if the cache is near full capacity.
AggregateStatsCache.AggrColStats	get(String dbName, String tblName, String colName, List<String> partNames) Return aggregate stats for a column from the cache or null.
int	getCurrentNodes()
float	getFalsePositiveProbability()
float	getFullPercent()
Float	getHitRatio()
static AggregateStatsCache	getInstance(org.apache.hadoop.conf.Configuration conf)
int	getMaxCacheNodes()
int	getMaxPartsPerCacheNode()

Methods inherited from class java.lang.Object

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

Method Detail

getInstance

public static AggregateStatsCache getInstance(org.apache.hadoop.conf.Configuration conf)

getMaxCacheNodes

public int getMaxCacheNodes()

getCurrentNodes

public int getCurrentNodes()

getFullPercent

public float getFullPercent()

getMaxPartsPerCacheNode

public int getMaxPartsPerCacheNode()

getFalsePositiveProbability

public float getFalsePositiveProbability()

getHitRatio

public Float getHitRatio()

get

public AggregateStatsCache.AggrColStats get(String dbName,
                                   String tblName,
                                   String colName,
                                   List<String> partNames)

Return aggregate stats for a column from the cache or null. While reading from the nodelist for a key, we wait maxReaderWaitTime to acquire the lock, failing which we return a cache miss (i.e. null)

Parameters:

dbName -

tblName -

colName -

partNames -

Returns:

add

public void add(String dbName,
       String tblName,
       String colName,
       long numPartsCached,
       ColumnStatisticsObj colStats,
       BloomFilter bloomFilter)

Add a new node to the cache; may trigger the cleaner thread if the cache is near full capacity. We'll however add the node even if we temporaily exceed maxCacheNodes, because the cleaner will eventually create space from expired nodes or by removing LRU nodes.

Parameters:

dbName -

tblName -

colName -

numPartsCached -

colStats -

bloomFilter -