org.h2.index

Class VirtualConstructedTableIndex

java.lang.Object

org.h2.engine.DbObject

org.h2.schema.SchemaObject

org.h2.index.Index

org.h2.index.VirtualTableIndex

org.h2.index.VirtualConstructedTableIndex

All Implemented Interfaces:

HasSQL

public class VirtualConstructedTableIndex
extends VirtualTableIndex

An index for a virtual table that returns a result set. Search in this index performs scan over all rows and should be avoided.

Field Summary

Fields inherited from class org.h2.index.Index

columnIds, columns, indexColumns, indexType, 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 and Description
VirtualConstructedTableIndex(VirtualConstructedTable table, IndexColumn[] columns)

Method Summary

Modifier and Type	Method and Description
boolean	canScan() Can this index iterate over all rows?
Cursor	find(SessionLocal session, SearchRow first, SearchRow last) Find a row or a list of rows and create a cursor to iterate over the result.
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.
java.lang.String	getPlanSQL() Get the message to show in a EXPLAIN statement.
boolean	isFindUsingFullTableScan() Returns true if find() implementation performs scan over all index, false if find() performs the fast lookup.

Methods inherited from class org.h2.index.VirtualTableIndex

add, checkRename, close, getRowCount, getRowCountApproximation, needRebuild, remove, remove, truncate

Methods inherited from class org.h2.index.Index

canFindNext, canGetFirstOrLast, checkIndexColumnTypes, compareRows, findFirstOrLast, findNext, getColumnIndex, getColumns, getCostRangeIndex, getCreateSQL, getCreateSQLForCopy, getDiskSpaceUsed, getDuplicateKeyException, getDuplicatePrimaryKeyMessage, getIndexColumns, getIndexType, getRow, getRowFactory, getTable, getType, getUniqueColumnCount, getUniqueRowFactory, isFirstColumn, isHidden, 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 Detail

VirtualConstructedTableIndex

public VirtualConstructedTableIndex(VirtualConstructedTable table,
                                    IndexColumn[] columns)

Method Detail

isFindUsingFullTableScan

public boolean isFindUsingFullTableScan()

Description copied from class: Index

Returns true if find() implementation performs scan over all index, false if find() performs the fast lookup.

Overrides:

isFindUsingFullTableScan in class Index

Returns:

true if find() implementation performs scan over all index, false if find() performs the fast lookup

find

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

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

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

getPlanSQL

public java.lang.String getPlanSQL()

Description copied from class: Index

Get the message to show in a EXPLAIN statement.

Overrides:

getPlanSQL in class Index

Returns:

the plan

canScan

public boolean canScan()

Description copied from class: Index

Can this index iterate over all rows?

Overrides:

canScan in class Index

Returns:

true if it can