org.apache.cassandra.cql.common
Class RowSourceDef
java.lang.Object
org.apache.cassandra.cql.common.RowSourceDef
- Direct Known Subclasses:
- ColumnRangeQueryRSD, SuperColumnRangeQueryRSD, UniqueKeyQueryRSD
public abstract class RowSourceDef
- extends java.lang.Object
The abstract notion of a row source definition. A row source
is literally just anything that returns rows back.
The concrete implementations of row source might be things like a
column family row source, a "super column family" row source,
a table row source, etc.
Note: Instances of sub-classes of this class are part of the "shared"
execution plan of CQL. And hence they should not contain any mutable
(i.e. session specific) execution state. Mutable state, such a bind
variable values (corresponding to say a rowKey or a column Key) are
note part of the RowSourceDef tree.
[Eventually the notion of a "mutable" portion of the RowSource (RowSourceMut)
will be introduced to hold session-specific execution state of the RowSource.
For example, this would be needed when implementing iterator style rowsources
that yields rows back one at a time as opposed to returning them in one
shot.]
Method Summary |
abstract java.lang.String |
explainPlan()
|
abstract java.util.List<java.util.Map<java.lang.String,java.lang.String>> |
getRows()
|
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
RowSourceDef
public RowSourceDef()
getRows
public abstract java.util.List<java.util.Map<java.lang.String,java.lang.String>> getRows()
explainPlan
public abstract java.lang.String explainPlan()
Copyright © 2009 The Apache Software Foundation