org.h2.index
Class ScanIndex

java.lang.Object
  extended by org.h2.engine.DbObjectBase
      extended by org.h2.schema.SchemaObjectBase
          extended by org.h2.index.BaseIndex
              extended by org.h2.index.ScanIndex
All Implemented Interfaces:
DbObject, Index, RowIndex, SchemaObject

public class ScanIndex
extends BaseIndex
implements RowIndex

The scan index is not really an 'index' in the strict sense, because it can not be used for direct lookup. It can only be used to iterate over all rows of a table. Each regular table has one such object, even if no primary key or indexes are defined.


Field Summary
 
Fields inherited from class org.h2.index.BaseIndex
columnIds, columns, indexColumns, indexType, isMultiVersion, table
 
Fields inherited from class org.h2.engine.DbObjectBase
comment, database, trace
 
Fields inherited from interface org.h2.index.Index
EMPTY_HEAD
 
Fields inherited from interface org.h2.engine.DbObject
AGGREGATE, COMMENT, CONSTANT, CONSTRAINT, FUNCTION_ALIAS, INDEX, RIGHT, ROLE, SCHEMA, SEQUENCE, SETTING, TABLE_OR_VIEW, TRIGGER, USER, USER_DATATYPE
 
Constructor Summary
ScanIndex(TableData table, int id, IndexColumn[] columns, IndexType indexType)
           
 
Method Summary
 void add(Session session, Row row)
          Add a row to this index.
 boolean canGetFirstOrLast()
          Check if this index can quickly find the first or last value.
 void checkRename()
          Check if this object can be renamed.
 void close(Session session)
          Close this index.
 void commit(int operation, Row row)
          Commit the operation for a row.
 Cursor find(Session session, SearchRow first, SearchRow last)
          Create a cursor to iterate over a number of rows.
 Cursor findFirstOrLast(Session session, boolean first)
          Find the first (or last) value of this index.
 int getColumnIndex(Column col)
          Get the index of a column in the list of index columns
 double getCost(Session session, int[] masks)
          Calculate the cost to find rows.
 java.lang.String getCreateSQL()
          Build a SQL statement to re-create this object.
 Row getRow(Session session, long key)
          Get the row with the given key.
 long getRowCount(Session session)
          Get the row count of this table, for the given session.
 long getRowCountApproximation()
          Get the approximated row count for this table.
 boolean needRebuild()
          Check if this index needs to be re-built.
 void remove(Session session)
          Remove the index.
 void remove(Session session, Row row)
          Remove a row from the index.
 void truncate(Session session)
          Truncate the index.
 
Methods inherited from class org.h2.index.BaseIndex
canFindNext, compareKeys, compareRows, containsNullAndAllowMultipleNull, findNext, getColumnListSQL, getColumns, getCostRangeIndex, getCreateSQLForCopy, getDropSQL, getDuplicateKeyException, getIndexColumns, getIndexType, getLookupCost, getPlanSQL, getRootPageId, getTable, getType, removeChildrenAndResources
 
Methods inherited from class org.h2.schema.SchemaObjectBase
getSchema, getSQL, initSchemaObjectBase
 
Methods inherited from class org.h2.engine.DbObjectBase
getChildren, getComment, getDatabase, getHeadPos, getId, getModificationId, getName, initDbObjectBase, invalidate, isTemporary, rename, setComment, setModified, setObjectName, setTemporary, toString
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 
Methods inherited from interface org.h2.index.Index
canFindNext, compareKeys, compareRows, containsNullAndAllowMultipleNull, findNext, getColumnListSQL, getColumns, getCostRangeIndex, getDuplicateKeyException, getIndexColumns, getIndexType, getLookupCost, getPlanSQL, getRootPageId, getTable
 
Methods inherited from interface org.h2.schema.SchemaObject
getSchema
 
Methods inherited from interface org.h2.engine.DbObject
getChildren, getComment, getCreateSQLForCopy, getDatabase, getDropSQL, getHeadPos, getId, getModificationId, getName, getSQL, getType, isTemporary, removeChildrenAndResources, rename, setComment, setModified, setTemporary
 

Constructor Detail

ScanIndex

public ScanIndex(TableData table,
                 int id,
                 IndexColumn[] columns,
                 IndexType indexType)
Method Detail

remove

public void remove(Session session)
            throws java.sql.SQLException
Description copied from class: BaseIndex
Remove the index.

Specified by:
remove in interface Index
Specified by:
remove in class BaseIndex
Parameters:
session - the session
Throws:
java.sql.SQLException

truncate

public void truncate(Session session)
              throws java.sql.SQLException
Description copied from class: BaseIndex
Truncate the index.

Specified by:
truncate in interface Index
Specified by:
truncate in class BaseIndex
Parameters:
session - the session
Throws:
java.sql.SQLException

getCreateSQL

public java.lang.String getCreateSQL()
Description copied from class: DbObjectBase
Build a SQL statement to re-create this object.

Specified by:
getCreateSQL in interface DbObject
Overrides:
getCreateSQL in class BaseIndex
Returns:
the SQL statement

close

public void close(Session session)
Description copied from class: BaseIndex
Close this index.

Specified by:
close in interface Index
Specified by:
close in class BaseIndex
Parameters:
session - the session

getRow

public Row getRow(Session session,
                  long key)
           throws java.sql.SQLException
Description copied from interface: RowIndex
Get the row with the given key.

Specified by:
getRow in interface RowIndex
Parameters:
session - the session
key - the unique key
Returns:
the row
Throws:
java.sql.SQLException

add

public void add(Session session,
                Row row)
         throws java.sql.SQLException
Description copied from class: BaseIndex
Add a row to this index.

Specified by:
add in interface Index
Specified by:
add in class BaseIndex
Parameters:
session - the session
row - the row to add
Throws:
java.sql.SQLException

commit

public void commit(int operation,
                   Row row)
Description copied from interface: Index
Commit the operation for a row. This is only important for multi-version indexes.

Specified by:
commit in interface Index
Overrides:
commit in class BaseIndex
Parameters:
operation - the operation type
row - the row

remove

public void remove(Session session,
                   Row row)
            throws java.sql.SQLException
Description copied from class: BaseIndex
Remove a row from the index.

Specified by:
remove in interface Index
Specified by:
remove in class BaseIndex
Parameters:
session - the session
row - the row
Throws:
java.sql.SQLException

find

public Cursor find(Session session,
                   SearchRow first,
                   SearchRow last)
Description copied from class: BaseIndex
Create a cursor to iterate over a number of rows.

Specified by:
find in interface Index
Specified by:
find in class BaseIndex
Parameters:
session - the session
first - the first row to return (null if no limit)
last - the last row to return (null if no limit)
Returns:
the cursor to iterate over the results

getCost

public double getCost(Session session,
                      int[] masks)
Description copied from class: BaseIndex
Calculate the cost to find rows.

Specified by:
getCost in interface Index
Specified by:
getCost in class BaseIndex
Parameters:
session - the session
masks - the condition mask
Returns:
the cost

getRowCount

public long getRowCount(Session session)
Description copied from interface: Index
Get the row count of this table, for the given session.

Specified by:
getRowCount in interface Index
Parameters:
session - the session
Returns:
the row count

getColumnIndex

public int getColumnIndex(Column col)
Description copied from interface: Index
Get the index of a column in the list of index columns

Specified by:
getColumnIndex in interface Index
Overrides:
getColumnIndex in class BaseIndex
Parameters:
col - the column
Returns:
the index (0 meaning first column)

checkRename

public void checkRename()
                 throws java.sql.SQLException
Description copied from class: DbObjectBase
Check if this object can be renamed. System objects may not be renamed.

Specified by:
checkRename in interface DbObject
Specified by:
checkRename in class DbObjectBase
Throws:
java.sql.SQLException - if renaming is not allowed

needRebuild

public boolean needRebuild()
Description copied from class: BaseIndex
Check if this index needs to be re-built.

Specified by:
needRebuild in interface Index
Specified by:
needRebuild in class BaseIndex
Returns:
true if it must be re-built.

canGetFirstOrLast

public boolean canGetFirstOrLast()
Description copied from class: BaseIndex
Check if this index can quickly find the first or last value.

Specified by:
canGetFirstOrLast in interface Index
Specified by:
canGetFirstOrLast in class BaseIndex
Returns:
true if it can

findFirstOrLast

public Cursor findFirstOrLast(Session session,
                              boolean first)
                       throws java.sql.SQLException
Description copied from class: BaseIndex
Find the first (or last) value of this index. The cursor returned is positioned on the correct row, or on null if no row has been found.

Specified by:
findFirstOrLast in interface Index
Specified by:
findFirstOrLast in class BaseIndex
Parameters:
session - the session
first - true for the first value, false for the last
Returns:
a cursor (never null)
Throws:
java.sql.SQLException

getRowCountApproximation

public long getRowCountApproximation()
Description copied from interface: Index
Get the approximated row count for this table.

Specified by:
getRowCountApproximation in interface Index
Returns:
the approximated row count