org.apache.flume.channel.jdbc.impl
Class DerbySchemaHandler

java.lang.Object
  extended by 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
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
protected DerbySchemaHandler(DataSource dataSource)
           
 
Method Summary
 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.


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