| java.lang.Object
 org.apache.derby.impl.sql.execute.AggregatorInfo
| AggregatorInfo | | public class AggregatorInfo implements Formatable(Code) | | This is a simple class used to store the run time information
needed to invoke an aggregator. This class is serializable
because it is stored with the plan. It is serializable rather
than externalizable because it isn't particularly complicated
and presumbably we don't need version control on plans.
author:
jamie |
| aggregateName | | String aggregateName(Code) | | This class implements Formatable. That means that it
can write itself to and from a formatted stream. If
you add more fields to this class, make sure that you
also write/read them with the writeExternal()/readExternal()
methods.
If, inbetween releases, you add more fields to this class,
then you should bump the version number emitted by the getTypeFormatId()
method. OR, since this is something that is used
in stored prepared statements, it is ok to change it
if you make sure that stored prepared statements are
invalidated across releases.
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| aggregatorColumn | | int aggregatorColumn(Code) | | |
| inputColumn | | int inputColumn(Code) | | |
| isDistinct | | boolean isDistinct(Code) | | |
| outputColumn | | int outputColumn(Code) | | |
| AggregatorInfo | | public AggregatorInfo()(Code) | | Niladic constructor for Formattable
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| AggregatorInfo | | public AggregatorInfo(String aggregateName, String aggregatorClassName, int inputColNum, int outputColNum, int aggregatorColNum, boolean isDistinct, ResultDescription rd)(Code) | | Consructor
Parameters:
aggregateName - the name of the aggregate. Notactually used anywhere except diagnostics. Shouldbe the names as found in the language (e.g. MAX).
Parameters:
aggregatorClassName - the name of the aggregatorused to process this aggregate. Aggregator expectedto have a null arg constructor and implementAggregator.
Parameters:
inputColNum - the input column number
Parameters:
outputColNum - the output column number
Parameters:
aggregatorColNum - the column number in which the aggregator is stored.
Parameters:
isDistinct - if it is a distinct aggregate
Parameters:
rd - the result description |
| getAggregateName | | public String getAggregateName()(Code) | | Get the name of the aggergate (e.g. MAX)
the aggeregate name |
| getAggregatorClassName | | public String getAggregatorClassName()(Code) | | Get the name of the class that implements the user
aggregator for this class.
the aggeregator class name |
| getAggregatorColNum | | public int getAggregatorColNum()(Code) | | Get the column number for the aggregator
column.
the aggeregator colid |
| getInputColNum | | public int getInputColNum()(Code) | | Get the column number for the input
(addend) column.
the aggeregator colid |
| getOutputColNum | | public int getOutputColNum()(Code) | | Get the column number for the output
(result) column.
the aggeregator colid |
| getResultDescription | | public ResultDescription getResultDescription()(Code) | | Get the result description for the input value
to this aggregate.
the rd |
| getTypeFormatId | | public int getTypeFormatId()(Code) | | Get the formatID which corresponds to this class.
the formatID of this class |
| isDistinct | | public boolean isDistinct()(Code) | | Is the aggergate distinct
whether it is distinct |
| toString | | public String toString()(Code) | | Get a string for the object
string |
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