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java.lang.Objectorg.apache.hadoop.hbase.HColumnDescriptor
public class HColumnDescriptor
An HColumnDescriptor contains information about a column family such as the number of versions, compression settings, etc. It is used as input when creating a table or adding a column. Once set, the parameters that specify a column cannot be changed without deleting the column and recreating it. If there is data stored in the column, it will be deleted when the column is deleted.
Nested Class Summary | |
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static class |
HColumnDescriptor.CompressionType
The type of compression. |
Field Summary | |
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static String |
BLOCKCACHE
|
static String |
BLOOMFILTER
|
static String |
COMPRESSION
|
static boolean |
DEFAULT_BLOCKCACHE
Default setting for whether to use a block cache or not. |
static boolean |
DEFAULT_BLOOMFILTER
Default setting for whether or not to use bloomfilters. |
static HColumnDescriptor.CompressionType |
DEFAULT_COMPRESSION
Default compression type. |
static boolean |
DEFAULT_IN_MEMORY
Default setting for whether to serve from memory or not. |
static int |
DEFAULT_LENGTH
Default maximum cell length. |
static int |
DEFAULT_MAPFILE_INDEX_INTERVAL
Default mapfile index interval. |
static int |
DEFAULT_TTL
Default time to live of cell contents. |
static int |
DEFAULT_VERSIONS
Default number of versions of a record to keep. |
static String |
FOREVER
|
static String |
LENGTH
|
static String |
MAPFILE_INDEX_INTERVAL
|
static String |
TTL
|
protected Map<ImmutableBytesWritable,ImmutableBytesWritable> |
values
|
Constructor Summary | |
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HColumnDescriptor()
Default constructor. |
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HColumnDescriptor(byte[] columnName)
Construct a column descriptor specifying only the family name The other attributes are defaulted. |
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HColumnDescriptor(byte[] columnName,
int maxVersions,
HColumnDescriptor.CompressionType compression,
boolean inMemory,
boolean blockCacheEnabled,
int maxValueLength,
int timeToLive,
boolean bloomFilter)
Constructor |
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HColumnDescriptor(HColumnDescriptor desc)
Constructor. |
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HColumnDescriptor(String columnName)
Construct a column descriptor specifying only the family name The other attributes are defaulted. |
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HColumnDescriptor(org.apache.hadoop.io.Text columnName)
Construct a column descriptor specifying only the family name The other attributes are defaulted. |
Methods inherited from class java.lang.Object |
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clone, finalize, getClass, notify, notifyAll, wait, wait, wait |
Field Detail |
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public static final String COMPRESSION
public static final String BLOCKCACHE
public static final String LENGTH
public static final String TTL
public static final String BLOOMFILTER
public static final String FOREVER
public static final String MAPFILE_INDEX_INTERVAL
public static final HColumnDescriptor.CompressionType DEFAULT_COMPRESSION
public static final int DEFAULT_VERSIONS
public static final int DEFAULT_LENGTH
public static final boolean DEFAULT_IN_MEMORY
public static final boolean DEFAULT_BLOCKCACHE
public static final boolean DEFAULT_BLOOMFILTER
public static final int DEFAULT_TTL
public static final int DEFAULT_MAPFILE_INDEX_INTERVAL
protected Map<ImmutableBytesWritable,ImmutableBytesWritable> values
Constructor Detail |
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public HColumnDescriptor()
public HColumnDescriptor(String columnName)
columnName
- - column family namepublic HColumnDescriptor(org.apache.hadoop.io.Text columnName)
columnName
- - column family namepublic HColumnDescriptor(byte[] columnName)
columnName
- Column family name. Must have the ':' ending.public HColumnDescriptor(HColumnDescriptor desc)
desc
- The descriptor.public HColumnDescriptor(byte[] columnName, int maxVersions, HColumnDescriptor.CompressionType compression, boolean inMemory, boolean blockCacheEnabled, int maxValueLength, int timeToLive, boolean bloomFilter)
columnName
- Column family name. Must have the ':' ending.maxVersions
- Maximum number of versions to keepcompression
- Compression typeinMemory
- If true, column data should be kept in an HRegionServer's
cacheblockCacheEnabled
- If true, MapFile blocks should be cachedmaxValueLength
- Restrict values to <= this valuetimeToLive
- Time-to-live of cell contents, in seconds from last timestamp
(use HConstants.FOREVER for unlimited TTL)bloomFilter
- Enable the specified bloom filter for this column
IllegalArgumentException
- if passed a family name that is made of
other than 'word' characters: i.e. [a-zA-Z_0-9]
and does not
end in a :
IllegalArgumentException
- if the number of versions is <= 0Method Detail |
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public static byte[] isLegalFamilyName(byte[] b)
b
- Family name.
b
IllegalArgumentException
- If not null and not a legitimate family
name: i.e. 'printable' and ends in a ':' (Null passes are allowed because
b
can be null when deserializing).public byte[] getName()
public byte[] getNameWithColon()
public String getNameAsString()
public byte[] getValue(byte[] key)
key
- The key.
public String getValue(String key)
key
- The key.
public void setValue(byte[] key, byte[] value)
key
- The key.value
- The value.public void setValue(String key, String value)
key
- The key.value
- The value.public HColumnDescriptor.CompressionType getCompression()
public int getMaxVersions()
public void setMaxVersions(int maxVersions)
maxVersions
- maximum number of versionspublic HColumnDescriptor.CompressionType getCompressionType()
public void setCompressionType(HColumnDescriptor.CompressionType type)
type
- Compression type setting.public boolean isInMemory()
public void setInMemory(boolean inMemory)
inMemory
- True if we are to keep all values in the HRegionServer
cachepublic int getMaxValueLength()
public void setMaxValueLength(int maxLength)
maxLength
- Maximum value length.public int getTimeToLive()
public void setTimeToLive(int timeToLive)
timeToLive
- public boolean isBlockCacheEnabled()
public void setBlockCacheEnabled(boolean blockCacheEnabled)
blockCacheEnabled
- True if MapFile blocks should be cached.public boolean isBloomfilter()
public void setBloomfilter(boolean onOff)
onOff
- Enable/Disable bloom filterpublic int getMapFileIndexInterval()
public void setMapFileIndexInterval(int interval)
interval
- The number of entries that are added to the store MapFile before
an index entry is added.public String toString()
toString
in class Object
public boolean equals(Object obj)
equals
in class Object
public int hashCode()
hashCode
in class Object
public void readFields(DataInput in) throws IOException
readFields
in interface org.apache.hadoop.io.Writable
IOException
public void write(DataOutput out) throws IOException
write
in interface org.apache.hadoop.io.Writable
IOException
public int compareTo(Object o)
compareTo
in interface Comparable
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