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java.lang.Object org.apache.accumulo.core.iterators.RowDeletingIterator
public class RowDeletingIterator
An iterator for deleting whole rows. After setting this iterator up for your table, to delete a row insert a row with empty column family, empty column qualifier, empty column visibility, and a value of DEL_ROW. Do not use empty columns for anything else when using this iterator. When using this iterator the locality group containing the row deletes will always be read. The locality group containing the empty column family will contain row deletes. Always reading this locality group can have an impact on performance. For example assume there are two locality groups, one containing large images and one containing small metadata about the images. If row deletes are in the same locality group as the images, then this will significantly slow down scans and major compactions that are only reading the metadata locality group. Therefore, you would want to put the empty column family in the locality group that contains the metadata. Another option is to put the empty column in its own locality group. Which is best depends on your data.
Field Summary | |
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static Value |
DELETE_ROW_VALUE
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Constructor Summary | |
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RowDeletingIterator()
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Method Summary | |
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SortedKeyValueIterator<Key,Value> |
deepCopy(IteratorEnvironment env)
Creates a deep copy of this iterator as though seek had not yet been called. |
Key |
getTopKey()
Returns top key. |
Value |
getTopValue()
Returns top value. |
boolean |
hasTop()
Returns true if the iterator has more elements. |
void |
init(SortedKeyValueIterator<Key,Value> source,
java.util.Map<java.lang.String,java.lang.String> options,
IteratorEnvironment env)
Initializes the iterator. |
void |
next()
Advances to the next K,V pair. |
void |
seek(Range range,
java.util.Collection<ByteSequence> columnFamilies,
boolean inclusive)
An iterator must seek to the first key in the range taking inclusiveness into account. |
Methods inherited from class java.lang.Object |
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clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Field Detail |
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public static final Value DELETE_ROW_VALUE
Constructor Detail |
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public RowDeletingIterator()
Method Detail |
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public SortedKeyValueIterator<Key,Value> deepCopy(IteratorEnvironment env)
SortedKeyValueIterator
deepCopy
in interface SortedKeyValueIterator<Key,Value>
env
- IteratorEnvironment environment in which iterator is being run.
public Key getTopKey()
SortedKeyValueIterator
getTopKey
in interface SortedKeyValueIterator<Key,Value>
public Value getTopValue()
SortedKeyValueIterator
getTopValue
in interface SortedKeyValueIterator<Key,Value>
public boolean hasTop()
SortedKeyValueIterator
hasTop
in interface SortedKeyValueIterator<Key,Value>
public void init(SortedKeyValueIterator<Key,Value> source, java.util.Map<java.lang.String,java.lang.String> options, IteratorEnvironment env) throws java.io.IOException
SortedKeyValueIterator
init
in interface SortedKeyValueIterator<Key,Value>
source
- SortedKeyValueIterator source to read data from.options
- Map map of string option names to option values.env
- IteratorEnvironment environment in which iterator is being run.
java.io.IOException
- unused.public void next() throws java.io.IOException
SortedKeyValueIterator
next
in interface SortedKeyValueIterator<Key,Value>
java.io.IOException
- if an I/O error occurs.public void seek(Range range, java.util.Collection<ByteSequence> columnFamilies, boolean inclusive) throws java.io.IOException
SortedKeyValueIterator
seek
in interface SortedKeyValueIterator<Key,Value>
range
- Range of keys to iterate over.columnFamilies
- Collection of column families to include or exclude.inclusive
- boolean that indicates whether to include (true) or exclude (false) column families.
java.io.IOException
- if an I/O error occurs.
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