DerbySchemaHandler (Apache Flume 1.9.0-cdh6.3.2 API)

java.lang.Object
- org.apache.flume.channel.jdbc.impl.DerbySchemaHandler

All Implemented Interfaces:

SchemaHandler
```
public class DerbySchemaHandler
extends Object
implements SchemaHandler
```
Schema handler for Derby Database. This handler uses the following schema:

FL_EVENT: The main event table. This table contains an auto-generated event ID along with the first 16kb of payload data. If the payload is larger than 16kb, a spill indicator flag is set and the remaining data is recorded in the FL_PLSPILL table.
```
 +-------------------------------+
 | FL_EVENT                      |
 +-------------------------------+
 | FLE_ID     : BIGINT PK        | (auto-gen sequence)
 | FLE_PAYLOAD: VARBINARY(16384) | (16kb payload)
 | FLE_SPILL  : BOOLEAN          | (true if payload spills)
 | FLE_CHANNEL: VARCHAR(64)      |
 +-------------------------------+
 
```
FL_PLSPILL: This table holds payloads in excess of 16kb and relates back to the FL_EVENT table using foreign key reference via FLP_EVENT column.
```
 +---------------------+
 | FL_PLSPILL          |
 +---------------------+
 | FLP_EVENT  : BIGINT | (FK into FL_EVENT.FLE_ID)
 | FLP_SPILL  : BLOB   |
 +---------------------+
 
```
FL_HEADER: The table that holds headers. This table contains name value pairs of headers less than or up to first 255 bytes each. If a name is longer than 255 bytes, a spill indicator flag is set and the remaining bytes are recorded in FL_NMSPILL table. Similarly if the value is longer than 255 bytes, a spill indicator flag is set and the remaining bytes are recorded in FL_VLSPILL table. Each header record relates back to the FL_EVENT table using foreign key reference via FLH_EVENT column.
```
 +--------------------------+
 | FL_HEADER                |
 +--------------------------+
 | FLH_ID     : BIGINT PK   | (auto-gen sequence)
 | FLH_EVENT  : BIGINT      | (FK into FL_EVENT.FLE_ID)
 | FLH_NAME   : VARCHAR(251)|
 | FLH_VALUE  : VARCHAR(251)|
 | FLH_NMSPILL: BOOLEAN     | (true if name spills)
 | FLH_VLSPILL: BOOLEAN     | (true if value spills)
 +--------------------------+
 
```
FL_NMSPILL: The table that holds header names in excess of 255 bytes and relates back to the FL_HEADER table using foreign key reference via FLN_HEADER column.
```
 +----------------------+
 | FL_NMSPILL           |
 +----------------------+
 | FLN_HEADER  : BIGINT | (FK into FL_HEADER.FLH_ID)
 | FLN_SPILL   : CLOB   |
 +----------------------+
 
```
FL_VLSPILL: The table that holds header values in excess of 255 bytes and relates back to the FL_HEADER table using foreign key reference via FLV_HEADER column.
```
 +----------------------+
 | FL_VLSPILL           |
 +----------------------+
 | FLV_HEADER  : BIGINT | (FK into FL_HEADER.FLH_ID)
 | FLV_SPILL   : CLOB   |
 +----------------------+
 
```
NOTE: The values that decide the spill boundary and storage length limits are defined in ConfigurationConstants class.
See Also:

ConfigurationConstants

Field Summary

Fields
Modifier and Type	Field and Description
`static String`	`COLUMN_LOOKUP_QUERY`
`static String`	`QUERY_CHANNEL_SIZE`
`static String`	`QUERY_CREATE_INDEX_FLE_CHANNEL`
`static String`	`QUERY_CREATE_INDEX_FLH_EVENT`
`static String`	`QUERY_CREATE_INDEX_FLN_HEADER`
`static String`	`QUERY_CREATE_INDEX_FLP_EVENT`
`static String`	`QUERY_CREATE_INDEX_FLV_HEADER`
`static String`	`QUERY_CREATE_SCHEMA_FLUME`
`static String`	`QUERY_CREATE_TABLE_FL_EVENT`
`static String`	`QUERY_CREATE_TABLE_FL_HEADER_FK`
`static String`	`QUERY_CREATE_TABLE_FL_HEADER_FMT`
`static String`	`QUERY_CREATE_TABLE_FL_HEADER_NOFK`
`static String`	`QUERY_CREATE_TABLE_FL_NMSPILL_FK`
`static String`	`QUERY_CREATE_TABLE_FL_NMSPILL_FMT`
`static String`	`QUERY_CREATE_TABLE_FL_NMSPILL_NOFK`
`static String`	`QUERY_CREATE_TABLE_FL_PLSPILL_FK`
`static String`	`QUERY_CREATE_TABLE_FL_PLSPILL_FMT`
`static String`	`QUERY_CREATE_TABLE_FL_PLSPILL_NOFK`
`static String`	`QUERY_CREATE_TABLE_FL_VLSPILL_FK`
`static String`	`QUERY_CREATE_TABLE_FL_VLSPILL_FMT`
`static String`	`QUERY_CREATE_TABLE_FL_VLSPILL_NOFK`
`static String`	`STMT_DELETE_EVENT_BASE`
`static String`	`STMT_DELETE_EVENT_SPILL`
`static String`	`STMT_DELETE_HEADER_BASE`
`static String`	`STMT_DELETE_HEADER_NAME_SPILL`
`static String`	`STMT_DELETE_HEADER_VALUE_SPILL`
`static String`	`STMT_FETCH_HEADER_BASE`
`static String`	`STMT_FETCH_HEADER_NAME_SPILL`
`static String`	`STMT_FETCH_HEADER_VALUE_SPILL`
`static String`	`STMT_FETCH_PAYLOAD_BASE`
`static String`	`STMT_FETCH_PAYLOAD_SPILL`
`static String`	`STMT_INSERT_EVENT_BASE`
`static String`	`STMT_INSERT_EVENT_SPILL`
`static String`	`STMT_INSERT_HEADER_BASE`
`static String`	`STMT_INSERT_HEADER_NAME_SPILL`
`static String`	`STMT_INSERT_HEADER_VALUE_SPILL`

Constructor Summary

Constructors
Modifier Constructor and Description

protected DerbySchemaHandler(DataSource dataSource)

Constructors
Modifier	Constructor and Description
`protected`	`DerbySchemaHandler(DataSource dataSource)`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`createSchemaObjects(boolean createForeignKeys, boolean createIndex)` Creates the schema.
`PersistableEvent`	`fetchAndDeleteEvent(String channel, Connection connection)` Retrieves the next persistent event from the database.
`long`	`getChannelSize(Connection connection)` Returns the current size of the channel using the connection specified that must have an active transaction ongoing.
`boolean`	`schemaExists()`
`void`	`storeEvent(PersistableEvent pe, Connection connection)` Inserts the given persistent event into the database.
`void`	`validateSchema()` Validates the schema.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - QUERY_CREATE_SCHEMA_FLUME
```
public static final String QUERY_CREATE_SCHEMA_FLUME
```
    See Also:
    
    Constant Field Values
  - QUERY_CREATE_TABLE_FL_EVENT
```
public static final String QUERY_CREATE_TABLE_FL_EVENT
```
  - QUERY_CREATE_INDEX_FLE_CHANNEL
```
public static final String QUERY_CREATE_INDEX_FLE_CHANNEL
```
    See Also:
    
    Constant Field Values
  - QUERY_CREATE_TABLE_FL_PLSPILL_FMT
```
public static final String QUERY_CREATE_TABLE_FL_PLSPILL_FMT
```
    See Also:
    
    Constant Field Values
  - QUERY_CREATE_TABLE_FL_PLSPILL_FK
```
public static final String QUERY_CREATE_TABLE_FL_PLSPILL_FK
```
  - QUERY_CREATE_TABLE_FL_PLSPILL_NOFK
```
public static final String QUERY_CREATE_TABLE_FL_PLSPILL_NOFK
```
  - QUERY_CREATE_INDEX_FLP_EVENT
```
public static final String QUERY_CREATE_INDEX_FLP_EVENT
```
    See Also:
    
    Constant Field Values
  - QUERY_CREATE_TABLE_FL_HEADER_FMT
```
public static final String QUERY_CREATE_TABLE_FL_HEADER_FMT
```
  - QUERY_CREATE_TABLE_FL_HEADER_FK
```
public static final String QUERY_CREATE_TABLE_FL_HEADER_FK
```
  - QUERY_CREATE_TABLE_FL_HEADER_NOFK
```
public static final String QUERY_CREATE_TABLE_FL_HEADER_NOFK
```
  - QUERY_CREATE_INDEX_FLH_EVENT
```
public static final String QUERY_CREATE_INDEX_FLH_EVENT
```
    See Also:
    
    Constant Field Values
  - QUERY_CREATE_TABLE_FL_NMSPILL_FMT
```
public static final String QUERY_CREATE_TABLE_FL_NMSPILL_FMT
```
  - QUERY_CREATE_TABLE_FL_NMSPILL_FK
```
public static final String QUERY_CREATE_TABLE_FL_NMSPILL_FK
```
  - QUERY_CREATE_TABLE_FL_NMSPILL_NOFK
```
public static final String QUERY_CREATE_TABLE_FL_NMSPILL_NOFK
```
  - QUERY_CREATE_INDEX_FLN_HEADER
```
public static final String QUERY_CREATE_INDEX_FLN_HEADER
```
    See Also:
    
    Constant Field Values
  - QUERY_CREATE_TABLE_FL_VLSPILL_FMT
```
public static final String QUERY_CREATE_TABLE_FL_VLSPILL_FMT
```
  - QUERY_CREATE_TABLE_FL_VLSPILL_FK
```
public static final String QUERY_CREATE_TABLE_FL_VLSPILL_FK
```
  - QUERY_CREATE_TABLE_FL_VLSPILL_NOFK
```
public static final String QUERY_CREATE_TABLE_FL_VLSPILL_NOFK
```
  - QUERY_CREATE_INDEX_FLV_HEADER
```
public static final String QUERY_CREATE_INDEX_FLV_HEADER
```
    See Also:
    
    Constant Field Values
  - COLUMN_LOOKUP_QUERY
```
public static final String COLUMN_LOOKUP_QUERY
```
    See Also:
    
    Constant Field Values
  - QUERY_CHANNEL_SIZE
```
public static final String QUERY_CHANNEL_SIZE
```
    See Also:
    
    Constant Field Values
  - STMT_INSERT_EVENT_BASE
```
public static final String STMT_INSERT_EVENT_BASE
```
    See Also:
    
    Constant Field Values
  - STMT_INSERT_EVENT_SPILL
```
public static final String STMT_INSERT_EVENT_SPILL
```
    See Also:
    
    Constant Field Values
  - STMT_INSERT_HEADER_BASE
```
public static final String STMT_INSERT_HEADER_BASE
```
    See Also:
    
    Constant Field Values
  - STMT_INSERT_HEADER_NAME_SPILL
```
public static final String STMT_INSERT_HEADER_NAME_SPILL
```
    See Also:
    
    Constant Field Values
  - STMT_INSERT_HEADER_VALUE_SPILL
```
public static final String STMT_INSERT_HEADER_VALUE_SPILL
```
    See Also:
    
    Constant Field Values
  - STMT_FETCH_PAYLOAD_BASE
```
public static final String STMT_FETCH_PAYLOAD_BASE
```
    See Also:
    
    Constant Field Values
  - STMT_FETCH_PAYLOAD_SPILL
```
public static final String STMT_FETCH_PAYLOAD_SPILL
```
    See Also:
    
    Constant Field Values
  - STMT_FETCH_HEADER_BASE
```
public static final String STMT_FETCH_HEADER_BASE
```
    See Also:
    
    Constant Field Values
  - STMT_FETCH_HEADER_NAME_SPILL
```
public static final String STMT_FETCH_HEADER_NAME_SPILL
```
    See Also:
    
    Constant Field Values
  - STMT_FETCH_HEADER_VALUE_SPILL
```
public static final String STMT_FETCH_HEADER_VALUE_SPILL
```
    See Also:
    
    Constant Field Values
  - STMT_DELETE_HEADER_VALUE_SPILL
```
public static final String STMT_DELETE_HEADER_VALUE_SPILL
```
    See Also:
    
    Constant Field Values
  - STMT_DELETE_HEADER_NAME_SPILL
```
public static final String STMT_DELETE_HEADER_NAME_SPILL
```
    See Also:
    
    Constant Field Values
  - STMT_DELETE_EVENT_SPILL
```
public static final String STMT_DELETE_EVENT_SPILL
```
    See Also:
    
    Constant Field Values
  - STMT_DELETE_HEADER_BASE
```
public static final String STMT_DELETE_HEADER_BASE
```
    See Also:
    
    Constant Field Values
  - STMT_DELETE_EVENT_BASE
```
public static final String STMT_DELETE_EVENT_BASE
```
    See Also:
    
    Constant Field Values
- Constructor Detail
  - DerbySchemaHandler
```
protected DerbySchemaHandler(DataSource dataSource)
```
- Method Detail
  - schemaExists
```
public boolean schemaExists()
```
    Specified by:
    
    schemaExists in interface SchemaHandler
    
    Returns:
    
    true if the schema exists. False otherwise.
  - createSchemaObjects
```
public void createSchemaObjects(boolean createForeignKeys,
                                boolean createIndex)
```
    Description copied from interface: SchemaHandler
    
    Creates the schema.
    
    Specified by:
    
    createSchemaObjects in interface SchemaHandler
    
    Parameters:
    
    createForeignKeys - a flag which indicates if the foreign key constraints should be created where necessary.
    
    createIndex - a flag which indicates if indexes must be created during the creation of the schema.
  - validateSchema
```
public void validateSchema()
```
    Description copied from interface: SchemaHandler
    
    Validates the schema.
    
    Specified by:
    
    validateSchema in interface SchemaHandler
  - storeEvent
```
public void storeEvent(PersistableEvent pe,
                       Connection connection)
```
    Description copied from interface: SchemaHandler
    
    Inserts the given persistent event into the database. The connection that is passed into the handler has an ongoing transaction and therefore the SchemaHandler implementation must not close the connection.
    
    Specified by:
    
    storeEvent in interface SchemaHandler
    
    Parameters:
    
    pe - the event to persist
    
    connection - the connection to use
  - fetchAndDeleteEvent
```
public PersistableEvent fetchAndDeleteEvent(String channel,
                                            Connection connection)
```
    Description copied from interface: SchemaHandler
    
    Retrieves the next persistent event from the database. The connection that is passed into the handler has an ongoing transaction and therefore the SchemaHandler implementation must not close the connection.
    
    Specified by:
    
    fetchAndDeleteEvent in interface SchemaHandler
    
    Parameters:
    
    channel - the channel name from which event will be retrieved
    
    connection - the connection to use
    
    Returns:
    
    the next persistent event if available or null
  - getChannelSize
```
public long getChannelSize(Connection connection)
```
    Description copied from interface: SchemaHandler
    
    Returns the current size of the channel using the connection specified that must have an active transaction ongoing. This allows the provider impl to enforce channel capacity limits when persisting events.
    
    Specified by:
    
    getChannelSize in interface SchemaHandler
    
    Returns:
    
    the current size of the channel.

Class DerbySchemaHandler

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

QUERY_CREATE_SCHEMA_FLUME

QUERY_CREATE_TABLE_FL_EVENT

QUERY_CREATE_INDEX_FLE_CHANNEL

QUERY_CREATE_TABLE_FL_PLSPILL_FMT

QUERY_CREATE_TABLE_FL_PLSPILL_FK

QUERY_CREATE_TABLE_FL_PLSPILL_NOFK

QUERY_CREATE_INDEX_FLP_EVENT

QUERY_CREATE_TABLE_FL_HEADER_FMT

QUERY_CREATE_TABLE_FL_HEADER_FK

QUERY_CREATE_TABLE_FL_HEADER_NOFK

QUERY_CREATE_INDEX_FLH_EVENT

QUERY_CREATE_TABLE_FL_NMSPILL_FMT

QUERY_CREATE_TABLE_FL_NMSPILL_FK

QUERY_CREATE_TABLE_FL_NMSPILL_NOFK

QUERY_CREATE_INDEX_FLN_HEADER

QUERY_CREATE_TABLE_FL_VLSPILL_FMT

QUERY_CREATE_TABLE_FL_VLSPILL_FK

QUERY_CREATE_TABLE_FL_VLSPILL_NOFK

QUERY_CREATE_INDEX_FLV_HEADER

COLUMN_LOOKUP_QUERY

QUERY_CHANNEL_SIZE

STMT_INSERT_EVENT_BASE

STMT_INSERT_EVENT_SPILL

STMT_INSERT_HEADER_BASE

STMT_INSERT_HEADER_NAME_SPILL

STMT_INSERT_HEADER_VALUE_SPILL

STMT_FETCH_PAYLOAD_BASE

STMT_FETCH_PAYLOAD_SPILL

STMT_FETCH_HEADER_BASE

STMT_FETCH_HEADER_NAME_SPILL

STMT_FETCH_HEADER_VALUE_SPILL

STMT_DELETE_HEADER_VALUE_SPILL

STMT_DELETE_HEADER_NAME_SPILL

STMT_DELETE_EVENT_SPILL

STMT_DELETE_HEADER_BASE

STMT_DELETE_EVENT_BASE

Constructor Detail

DerbySchemaHandler

Method Detail

schemaExists

createSchemaObjects

validateSchema

storeEvent

fetchAndDeleteEvent

getChannelSize