org.h2.index
Class BaseIndex

java.lang.Object
  org.h2.engine.DbObjectBase
      org.h2.schema.SchemaObjectBase
          org.h2.index.BaseIndex

All Implemented Interfaces:

DbObject, Index, SchemaObject

Direct Known Subclasses:

BaseHashIndex, BtreeIndex, FunctionIndex, LinkedIndex, MetaIndex, PageIndex, RangeIndex, ScanIndex, TreeIndex, ViewIndex

public abstract class BaseIndex
extends SchemaObjectBase
implements Index

Most index implementations extend the base index.

Field Summary

protected int[]	columnIds
protected Column[]	columns
protected IndexColumn[]	indexColumns
protected IndexType	indexType
protected boolean	isMultiVersion
protected Table	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

BaseIndex()

Method Summary

abstract void	add(Session session, Row row) Add a row to this index.
boolean	canFindNext() Check if the index can get the next higher value.
abstract boolean	canGetFirstOrLast() Check if this index can quickly find the first or last value.
abstract void	close(Session session) Close this index.
void	commit(int operation, Row row) Commit the operation for a row.
int	compareKeys(SearchRow rowData, SearchRow compare) Compare the positions of two rows.
int	compareRows(SearchRow rowData, SearchRow compare) Compare two rows.
boolean	containsNullAndAllowMultipleNull(SearchRow newRow) Check if one of the columns is NULL and multiple rows with NULL are allowed using the current compatibility mode for unique indexes.
abstract Cursor	find(Session session, SearchRow first, SearchRow last) Create a cursor to iterate over a number of rows.
abstract Cursor	findFirstOrLast(Session session, boolean first) Find the first (or last) value of this index.
Cursor	findNext(Session session, SearchRow higherThan, SearchRow last) Find a row or a list of rows that is larger and create a cursor to iterate over the result.
int	getColumnIndex(Column col) Get the index of a column in the list of index columns
java.lang.String	getColumnListSQL() Get the list of columns as a string.
Column[]	getColumns() Get the indexed columns.
abstract double	getCost(Session session, int[] masks) Calculate the cost to find rows.
long	getCostRangeIndex(int[] masks, long rowCount) Calculate the cost for the given mask as if this index was a typical b-tree range index.
java.lang.String	getCreateSQL() Build a SQL statement to re-create this object.
java.lang.String	getCreateSQLForCopy(Table table, java.lang.String quotedName) Build a SQL statement to re-create the object, or to create a copy of the object with a different name or referencing a different table
java.lang.String	getDropSQL() Build a SQL statement to drop this object.
java.sql.SQLException	getDuplicateKeyException() Create a duplicate key exception with a message that contains the index name
IndexColumn[]	getIndexColumns() Get the indexed columns as index columns (with ordering information).
IndexType	getIndexType() Get the index type.
int	getLookupCost(long rowCount) Estimate the cost required to search a number of rows.
java.lang.String	getPlanSQL() Get the message to show in a EXPLAIN statement.
int	getRootPageId() Get the root page of this index.
Table	getTable() Get the table on which this index is based.
int	getType() Get the object type.
abstract boolean	needRebuild() Check if this index needs to be re-built.
abstract void	remove(Session session) Remove the index.
abstract void	remove(Session session, Row row) Remove a row from the index.
void	removeChildrenAndResources(Session session) Remove all dependent objects and free all resources (files, blocks in files) of this object.
abstract void	truncate(Session session) Truncate the index.

Methods inherited from class org.h2.schema.SchemaObjectBase

getSchema, getSQL, initSchemaObjectBase

Methods inherited from class org.h2.engine.DbObjectBase

checkRename, 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

getRowCount, getRowCountApproximation

Methods inherited from interface org.h2.schema.SchemaObject

getSchema

Methods inherited from interface org.h2.engine.DbObject

checkRename, getChildren, getComment, getDatabase, getHeadPos, getId, getModificationId, getName, getSQL, isTemporary, rename, setComment, setModified, setTemporary

Field Detail

indexColumns

protected IndexColumn[] indexColumns

columns

protected Column[] columns

columnIds

protected int[] columnIds

table

protected Table table

indexType

protected IndexType indexType

isMultiVersion

protected boolean isMultiVersion

Constructor Detail

BaseIndex

public BaseIndex()

Method Detail

getRootPageId

public int getRootPageId()

Description copied from interface: Index

Get the root page of this index.

Specified by:

getRootPageId in interface Index

Returns:

the root page id

close

public abstract void close(Session session)
                    throws java.sql.SQLException

Close this index.

Specified by:

close in interface Index

Parameters:

session - the session

Throws:

java.sql.SQLException

add

public abstract void add(Session session,
                         Row row)
                  throws java.sql.SQLException

Add a row to this index.

Specified by:

add in interface Index

Parameters:

session - the session

row - the row to add

Throws:

java.sql.SQLException

remove

public abstract void remove(Session session,
                            Row row)
                     throws java.sql.SQLException

Remove a row from the index.

Specified by:

remove in interface Index

Parameters:

session - the session

row - the row

Throws:

java.sql.SQLException

find

public abstract Cursor find(Session session,
                            SearchRow first,
                            SearchRow last)
                     throws java.sql.SQLException

Create a cursor to iterate over a number of rows.

Specified by:

find in interface Index

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

Throws:

java.sql.SQLException

getCost

public abstract double getCost(Session session,
                               int[] masks)
                        throws java.sql.SQLException

Calculate the cost to find rows.

Specified by:

getCost in interface Index

Parameters:

session - the session

masks - the condition mask

Returns:

the cost

Throws:

java.sql.SQLException

remove

public abstract void remove(Session session)
                     throws java.sql.SQLException

Remove the index.

Specified by:

remove in interface Index

Parameters:

session - the session

Throws:

java.sql.SQLException

truncate

public abstract void truncate(Session session)
                       throws java.sql.SQLException

Truncate the index.

Specified by:

truncate in interface Index

Parameters:

session - the session

Throws:

java.sql.SQLException

canGetFirstOrLast

public abstract boolean canGetFirstOrLast()

Check if this index can quickly find the first or last value.

Specified by:

canGetFirstOrLast in interface Index

Returns:

true if it can

findFirstOrLast

public abstract Cursor findFirstOrLast(Session session,
                                       boolean first)
                                throws java.sql.SQLException

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

Parameters:

session - the session

first - true for the first value, false for the last

Returns:

a cursor (never null)

Throws:

java.sql.SQLException

needRebuild

public abstract boolean needRebuild()

Check if this index needs to be re-built.

Specified by:

needRebuild in interface Index

Returns:

true if it must be re-built.

getDropSQL

public java.lang.String getDropSQL()

Description copied from class: DbObjectBase

Build a SQL statement to drop this object.

Specified by:

getDropSQL in interface DbObject

Specified by:

getDropSQL in class DbObjectBase

Returns:

the SQL statement

getDuplicateKeyException

public java.sql.SQLException getDuplicateKeyException()

Description copied from interface: Index

Create a duplicate key exception with a message that contains the index name

Specified by:

getDuplicateKeyException in interface Index

Returns:

the exception

getPlanSQL

public java.lang.String getPlanSQL()

Description copied from interface: Index

Get the message to show in a EXPLAIN statement.

Specified by:

getPlanSQL in interface Index

Returns:

the plan

removeChildrenAndResources

public void removeChildrenAndResources(Session session)
                                throws java.sql.SQLException

Description copied from class: DbObjectBase

Remove all dependent objects and free all resources (files, blocks in files) of this object.

Specified by:

removeChildrenAndResources in interface DbObject

Specified by:

removeChildrenAndResources in class DbObjectBase

Parameters:

session - the session

Throws:

java.sql.SQLException

canFindNext

public boolean canFindNext()

Description copied from interface: Index

Check if the index can get the next higher value.

Specified by:

canFindNext in interface Index

Returns:

true if it can

findNext

public Cursor findNext(Session session,
                       SearchRow higherThan,
                       SearchRow last)
                throws java.sql.SQLException

Find a row or a list of rows that is larger and create a cursor to iterate over the result. The base implementation doesn't support this feature.

Specified by:

findNext in interface Index

Parameters:

session - the session

higherThan - the lower limit (excluding)

last - the last row, or null for no limit

Returns:

the cursor

Throws:

java.sql.SQLException

getLookupCost

public int getLookupCost(long rowCount)

Description copied from interface: Index

Estimate the cost required to search a number of rows.

Specified by:

getLookupCost in interface Index

Parameters:

rowCount - the row count

Returns:

the estimated cost

getCostRangeIndex

public long getCostRangeIndex(int[] masks,
                              long rowCount)

Calculate the cost for the given mask as if this index was a typical b-tree range index.

Specified by:

getCostRangeIndex in interface Index

Parameters:

masks - the search mask

rowCount - the number of rows in the index

Returns:

the calculated cost

compareRows

public int compareRows(SearchRow rowData,
                       SearchRow compare)
                throws java.sql.SQLException

Description copied from interface: Index

Compare two rows.

Specified by:

compareRows in interface Index

Parameters:

rowData - the first row

compare - the second row

Returns:

0 if both rows are equal, -1 if the first row is smaller, otherwise 1

Throws:

java.sql.SQLException

containsNullAndAllowMultipleNull

public boolean containsNullAndAllowMultipleNull(SearchRow newRow)

Description copied from interface: Index

Check if one of the columns is NULL and multiple rows with NULL are allowed using the current compatibility mode for unique indexes. Note: NULL behavior is complicated in SQL.

Specified by:

containsNullAndAllowMultipleNull in interface Index

Parameters:

newRow - the row to check

Returns:

true if one of the columns is null and multiple nulls in unique indexes are allowed

compareKeys

public int compareKeys(SearchRow rowData,
                       SearchRow compare)

Description copied from interface: Index

Compare the positions of two rows.

Specified by:

compareKeys in interface Index

Parameters:

rowData - the first row

compare - the second row

Returns:

0 if both rows are equal, -1 if the first row is smaller, otherwise 1

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

Parameters:

col - the column

Returns:

the index (0 meaning first column)

getColumnListSQL

public java.lang.String getColumnListSQL()

Description copied from interface: Index

Get the list of columns as a string.

Specified by:

getColumnListSQL in interface Index

Returns:

the list of columns

getCreateSQLForCopy

public java.lang.String getCreateSQLForCopy(Table table,
                                            java.lang.String quotedName)

Description copied from class: DbObjectBase

Build a SQL statement to re-create the object, or to create a copy of the object with a different name or referencing a different table

Specified by:

getCreateSQLForCopy in interface DbObject

Specified by:

getCreateSQLForCopy in class DbObjectBase

Parameters:

table - the new table name

quotedName - the new quoted name

Returns:

the SQL statement

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

Specified by:

getCreateSQL in class DbObjectBase

Returns:

the SQL statement

getIndexColumns

public IndexColumn[] getIndexColumns()

Description copied from interface: Index

Get the indexed columns as index columns (with ordering information).

Specified by:

getIndexColumns in interface Index

Returns:

the index columns

getColumns

public Column[] getColumns()

Description copied from interface: Index

Get the indexed columns.

Specified by:

getColumns in interface Index

Returns:

the columns

getIndexType

public IndexType getIndexType()

Description copied from interface: Index

Get the index type.

Specified by:

getIndexType in interface Index

Returns:

the index type

getType

public int getType()

Description copied from class: DbObjectBase

Get the object type.

Specified by:

getType in interface DbObject

Specified by:

getType in class DbObjectBase

Returns:

the object type

getTable

public Table getTable()

Description copied from interface: Index

Get the table on which this index is based.

Specified by:

getTable in interface Index

Returns:

the table

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

Parameters:

operation - the operation type

row - the row