Package org.h2.index

Class MetaIndex

java.lang.Object

org.h2.engine.DbObject

org.h2.schema.SchemaObject

org.h2.index.Index

org.h2.index.MetaIndex

All Implemented Interfaces:

HasSQL

public class MetaIndex
extends Index

The index implementation for meta data tables.

Field Summary

Fields inherited from class org.h2.index.Index

columnIds, columns, indexColumns, indexType, table, uniqueColumnColumn

Fields inherited from class org.h2.engine.DbObject

AGGREGATE, comment, COMMENT, CONSTANT, CONSTRAINT, database, DOMAIN, FUNCTION_ALIAS, INDEX, RIGHT, ROLE, SCHEMA, SEQUENCE, SETTING, SYNONYM, TABLE_OR_VIEW, trace, TRIGGER, USER

Fields inherited from interface org.h2.util.HasSQL

ADD_PLAN_INFORMATION, DEFAULT_SQL_FLAGS, NO_CASTS, QUOTE_ONLY_WHEN_REQUIRED, REPLACE_LOBS_FOR_TRACE, TRACE_SQL_FLAGS

Constructor Summary

Constructors

Constructor	Description
MetaIndex(MetaTable meta, IndexColumn[] columns, boolean scan)

Method Summary

Modifier and Type	Method	Description
void	add(SessionLocal session, Row row)	Add a row to the index.
void	checkRename()	Check if renaming is allowed.
void	close(SessionLocal session)	Close this index.
Cursor	find(SessionLocal session, SearchRow first, SearchRow last, boolean reverse)	Find a row or a list of rows 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
double	getCost(SessionLocal session, int[] masks, TableFilter[] filters, int filter, SortOrder sortOrder, AllColumnsForPlan allColumnsSet)	Estimate the cost to search for rows given the search mask.
String	getCreateSQL()	Construct the CREATE ...
long	getDiskSpaceUsed(boolean approximate)	Get the used disk space for this index.
String	getPlanSQL()	Get the message to show in a EXPLAIN statement.
long	getRowCount(SessionLocal session)	Get the row count of this table, for the given session.
long	getRowCountApproximation(SessionLocal session)	Get the approximated row count for this table.
boolean	isFirstColumn(Column column)	Check if the given column is the first for this index
boolean	needRebuild()	Check if the index needs to be rebuilt.
void	remove(SessionLocal session)	Remove the index.
void	remove(SessionLocal session, Row row)	Remove a row from the index.
void	truncate(SessionLocal session)	Remove all rows from the index.

Methods inherited from class org.h2.index.Index

canFindNext, canGetFirstOrLast, canScan, checkIndexColumnTypes, compareRows, findFirstOrLast, findNext, getColumns, getCostRangeIndex, getCreateSQLForCopy, getDuplicateKeyException, getDuplicatePrimaryKeyMessage, getIndexColumns, getIndexType, getRow, getRowFactory, getTable, getType, getUniqueColumnCount, getUniqueRowFactory, isFindUsingFullTableScan, isRowIdIndex, needsUniqueCheck, removeChildrenAndResources, update

Methods inherited from class org.h2.schema.SchemaObject

getSchema, getSQL, getSQL

Methods inherited from class org.h2.engine.DbObject

getChildren, getComment, getCreateSQLForMeta, getDatabase, getDropSQL, getId, getModificationId, getName, invalidate, isTemporary, isValid, 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.util.HasSQL

getTraceSQL

Constructor Details

MetaIndex

public MetaIndex(MetaTable meta,
 IndexColumn[] columns,
 boolean scan)

Method Details

close

public void close(SessionLocal session)

Description copied from class: Index

Close this index.

Specified by:

close in class Index

Parameters:

session - the session used to write data

add

public void add(SessionLocal session,
 Row row)

Description copied from class: Index

Add a row to the index.

Specified by:

add in class Index

Parameters:

session - the session to use

row - the row to add

remove

public void remove(SessionLocal session,
 Row row)

Description copied from class: Index

Remove a row from the index.

Specified by:

remove in class Index

Parameters:

session - the session

row - the row

find

public Cursor find(SessionLocal session,
 SearchRow first,
 SearchRow last,
 boolean reverse)

Description copied from class: Index

Find a row or a list of rows and create a cursor to iterate over the result.

Specified by:

find in class Index

Parameters:

session - the session

first - the first row, or null for no limit

last - the last row, or null for no limit

reverse - if true, iterate in reverse (descending) order

Returns:

the cursor to iterate over the results

getCost

public double getCost(SessionLocal session,
 int[] masks,
 TableFilter[] filters,
 int filter,
 SortOrder sortOrder,
 AllColumnsForPlan allColumnsSet)

Description copied from class: Index

Estimate the cost to search for rows given the search mask. There is one element per column in the search mask. For possible search masks, see IndexCondition.

Specified by:

getCost in class Index

Parameters:

session - the session

masks - per-column comparison bit masks, null means 'always false', see constants in IndexCondition

filters - all joined table filters

filter - the current table filter index

sortOrder - the sort order

allColumnsSet - the set of all columns

Returns:

the estimated cost

truncate

public void truncate(SessionLocal session)

Description copied from class: Index

Remove all rows from the index.

Specified by:

truncate in class Index

Parameters:

session - the session

remove

public void remove(SessionLocal session)

Description copied from class: Index

Remove the index.

Specified by:

remove in class Index

Parameters:

session - the session

getColumnIndex

public int getColumnIndex(Column col)

Description copied from class: Index

Get the index of a column in the list of index columns

Overrides:

getColumnIndex in class Index

Parameters:

col - the column

Returns:

the index (0 meaning first column)

isFirstColumn

public boolean isFirstColumn(Column column)

Description copied from class: Index

Check if the given column is the first for this index

Overrides:

isFirstColumn in class Index

Parameters:

column - the column

Returns:

true if the given columns is the first

checkRename

public void checkRename()

Description copied from class: DbObject

Check if renaming is allowed. Does nothing when allowed.

Overrides:

checkRename in class DbObject

needRebuild

public boolean needRebuild()

Description copied from class: Index

Check if the index needs to be rebuilt. This method is called after opening an index.

Specified by:

needRebuild in class Index

Returns:

true if a rebuild is required.

getCreateSQL

public String getCreateSQL()

Description copied from class: DbObject

Construct the CREATE ... SQL statement for this object.

Overrides:

getCreateSQL in class Index

Returns:

the SQL statement

getRowCount

public long getRowCount(SessionLocal session)

Description copied from class: Index

Get the row count of this table, for the given session.

Specified by:

getRowCount in class Index

Parameters:

session - the session

Returns:

the row count

getRowCountApproximation

public long getRowCountApproximation(SessionLocal session)

Description copied from class: Index

Get the approximated row count for this table.

Specified by:

getRowCountApproximation in class Index

Parameters:

session - the session

Returns:

the approximated row count

getDiskSpaceUsed

public long getDiskSpaceUsed(boolean approximate)

Description copied from class: Index

Get the used disk space for this index.

Overrides:

getDiskSpaceUsed in class Index

Parameters:

approximate - true to return quick approximation

Returns:

the estimated number of bytes

getPlanSQL

public String getPlanSQL()

Description copied from class: Index

Get the message to show in a EXPLAIN statement.

Overrides:

getPlanSQL in class Index

Returns:

the plan