DataSourceIF (Ontopia)

All Known Implementing Classes:

CSVDataSource, JDBCDataSource
```
public interface DataSourceIF
```
INTERNAL: A data source interface. This interface is used to represent a data source that is capable of returning a stream of tuples for a limited number of relations.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`void`	`close()`	INTERNAL: Closes the data source so that it can release any open resources.
`ChangelogReaderIF`	`getChangelogReader(Changelog changelog, String startOrder)`	INTERNAL: Returns a changelog reader.
`String`	`getMaxOrderValue(Changelog changelog)`	INTERNAL: Returns the maximum value of the order column for the specified changelog.
`TupleReaderIF`	`getReader(String relation)`	INTERNAL: Returns a tuple reader for the given relation.
`Collection<Relation>`	`getRelations()`	INTERNAL: Returns the relations that the data source knows of.

- Method Detail
  - getRelations
```
Collection<Relation> getRelations()
```
    INTERNAL: Returns the relations that the data source knows of. The collection return contains Relation instances.
  - getReader
```
TupleReaderIF getReader(String relation)
```
    INTERNAL: Returns a tuple reader for the given relation.
  - getChangelogReader
```
ChangelogReaderIF getChangelogReader(Changelog changelog,
                                     String startOrder)
```
    INTERNAL: Returns a changelog reader.
  - getMaxOrderValue
```
String getMaxOrderValue(Changelog changelog)
```
    INTERNAL: Returns the maximum value of the order column for the specified changelog.
  - close
```
void close()
```
    INTERNAL: Closes the data source so that it can release any open resources.