org.apache.derby.impl.sql.execute
Class CreateIndexConstantAction

java.lang.Object
  org.apache.derby.impl.sql.execute.DDLConstantAction
      org.apache.derby.impl.sql.execute.DDLSingleTableConstantAction
          org.apache.derby.impl.sql.execute.IndexConstantAction
              org.apache.derby.impl.sql.execute.CreateIndexConstantAction

All Implemented Interfaces:

ConstantAction

 class CreateIndexConstantAction
extends IndexConstantAction

ConstantAction to create an index either through a CREATE INDEX statement or as a backing index to a constraint.

Field Summary

private java.lang.String[]	columnNames
private UUID	conglomerateUUID
private long	conglomId Conglomerate number for the conglomerate created by this constant action; -1L if this constant action has not been executed.
private long	droppedConglomNum Conglomerate number of the physical conglomerate that we will "replace" using this constant action.
private boolean	forCreateTable Is this for a CREATE TABLE, i.e. it is for a constraint declared in a CREATE TABLE statement that requires a backing index.
private ExecRow	indexTemplateRow
private java.lang.String	indexType
private boolean[]	isAscending
private boolean	isConstraint
private java.util.Properties	properties
private boolean	unique
private boolean	uniqueWithDuplicateNulls

Fields inherited from class org.apache.derby.impl.sql.execute.IndexConstantAction

indexName, schemaName, tableName

Fields inherited from class org.apache.derby.impl.sql.execute.DDLSingleTableConstantAction

tableId

Constructor Summary

CreateIndexConstantAction(boolean forCreateTable, boolean unique, boolean uniqueWithDuplicateNulls, java.lang.String indexType, java.lang.String schemaName, java.lang.String indexName, java.lang.String tableName, UUID tableId, java.lang.String[] columnNames, boolean[] isAscending, boolean isConstraint, UUID conglomerateUUID, java.util.Properties properties)
Make the ConstantAction to create an index.

CreateIndexConstantAction(ConglomerateDescriptor srcCD, TableDescriptor td, java.util.Properties properties)
Make a ConstantAction that creates a new physical conglomerate based on index information stored in the received descriptors.

Method Summary

private boolean	addStatistics(DataDictionary dd, IndexRowGenerator irg, long numRows) Determines if a statistics entry is to be added for the index.
void	executeConstantAction(Activation activation) This is the guts of the Execution-time logic for creating an index.
(package private) long	getCreatedConglomNumber() Get the conglomerate number for the conglomerate that was created by this constant action.
(package private) UUID	getCreatedUUID() Get the UUID for the conglomerate descriptor that was created (or re-used) by this constant action.
(package private) ExecRow	getIndexTemplateRow()
(package private) long	getReplacedConglomNumber() If the purpose of this constant action was to "replace" a dropped physical conglomerate, then this method returns the conglomerate number of the dropped conglomerate.
private RowLocationRetRowSource	loadSorter(ExecRow[] baseRows, ExecIndexRow[] indexRows, TransactionController tc, GroupFetchScanController scan, long sortId, RowLocation[] rl) Scan the base conglomerate and insert the keys into a sorter, returning a rowSource on the sorter.
java.lang.String	toString()

Methods inherited from class org.apache.derby.impl.sql.execute.IndexConstantAction

getIndexName, setIndexName

Methods inherited from class org.apache.derby.impl.sql.execute.DDLSingleTableConstantAction

dropConglomerate, dropConglomerate, dropConstraint, dropConstraint, dropConstraint, executeConglomReplacement, getConglomReplacementAction, recreateUniqueConstraintBackingIndexAsUniqueWhenNotNull

Methods inherited from class org.apache.derby.impl.sql.execute.DDLConstantAction

addColumnDependencies, adjustUDTDependencies, adjustUDTDependencies, constructToString, getAndCheckSchemaDescriptor, getSchemaDescriptorForCreate, lockTableForDDL, storeConstraintDependenciesOnPrivileges, storeViewTriggerDependenciesOnPrivileges

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

forCreateTable

private final boolean forCreateTable

Is this for a CREATE TABLE, i.e. it is for a constraint declared in a CREATE TABLE statement that requires a backing index.

unique

private boolean unique

uniqueWithDuplicateNulls

private boolean uniqueWithDuplicateNulls

indexType

private java.lang.String indexType

columnNames

private java.lang.String[] columnNames

isAscending

private boolean[] isAscending

isConstraint

private boolean isConstraint

conglomerateUUID

private UUID conglomerateUUID

properties

private java.util.Properties properties

indexTemplateRow

private ExecRow indexTemplateRow

conglomId

private long conglomId

Conglomerate number for the conglomerate created by this constant action; -1L if this constant action has not been executed. If this constant action doesn't actually create a new conglomerate--which can happen if it finds an existing conglomerate that satisfies all of the criteria--then this field will hold the conglomerate number of whatever existing conglomerate was found.

droppedConglomNum

private long droppedConglomNum

Conglomerate number of the physical conglomerate that we will "replace" using this constant action. That is, if the purpose of this constant action is to create a new physical conglomerate to replace a dropped physical conglomerate, then this field holds the conglomerate number of the dropped physical conglomerate. If -1L then we are not replacing a conglomerate, we're simply creating a new index (and backing physical conglomerate) as normal.

Constructor Detail

CreateIndexConstantAction

CreateIndexConstantAction(boolean forCreateTable,
                          boolean unique,
                          boolean uniqueWithDuplicateNulls,
                          java.lang.String indexType,
                          java.lang.String schemaName,
                          java.lang.String indexName,
                          java.lang.String tableName,
                          UUID tableId,
                          java.lang.String[] columnNames,
                          boolean[] isAscending,
                          boolean isConstraint,
                          UUID conglomerateUUID,
                          java.util.Properties properties)

Make the ConstantAction to create an index.

Parameters:

forCreateTable - Being executed within a CREATE TABLE statement

unique - True means it will be a unique index

uniqueWithDuplicateNulls - True means index check and disallow any duplicate key if key has no column with a null value. If any column in the key has a null value, no checking is done and insert will always succeed.

indexType - type of index (BTREE, for example)

schemaName - schema that table (and index) lives in.

indexName - Name of the index

tableName - Name of table the index will be on

tableId - UUID of table

columnNames - Names of the columns in the index, in order

isAscending - Array of booleans telling asc/desc on each column

isConstraint - TRUE if index is backing up a constraint, else FALSE

conglomerateUUID - ID of conglomerate

properties - The optional properties list associated with the index.

CreateIndexConstantAction

CreateIndexConstantAction(ConglomerateDescriptor srcCD,
                          TableDescriptor td,
                          java.util.Properties properties)

Make a ConstantAction that creates a new physical conglomerate based on index information stored in the received descriptors. Assumption is that the received ConglomerateDescriptor is still valid (meaning it has corresponding entries in the system tables and it describes some constraint/index that has _not_ been dropped--though the physical conglomerate underneath has). This constructor is used in cases where the physical conglomerate for an index has been dropped but the index still exists. That can happen if multiple indexes share a physical conglomerate but then the conglomerate is dropped as part of "drop index" processing for one of the indexes. (Note that "indexes" here includes indexes which were created to back constraints.) In that case we have to create a new conglomerate to satisfy the remaining sharing indexes, so that's what we're here for. See ConglomerateDescriptor.drop() for details on when that is necessary.

Method Detail

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

executeConstantAction

public void executeConstantAction(Activation activation)
                           throws StandardException

This is the guts of the Execution-time logic for creating an index.

A index is represented as:

• ConglomerateDescriptor.

No dependencies are created.

Parameters:

activation - The execution environment for this constant action.

Throws:

StandardException - Thrown on failure

See Also:

ConglomerateDescriptor, SchemaDescriptor, ConstantAction.executeConstantAction(org.apache.derby.iapi.sql.Activation)

addStatistics

private boolean addStatistics(DataDictionary dd,
                              IndexRowGenerator irg,
                              long numRows)
                       throws StandardException

Determines if a statistics entry is to be added for the index.

As an optimization, it may be better to not write a statistics entry to SYS.SYSSTATISTICS. If it isn't needed by Derby as part of query optimization there is no reason to spend resources keeping the statistics up to date.

Parameters:

dd - the data dictionary

irg - the index row generator

numRows - the number of rows in the index

Returns:

true if statistics should be written to SYS.SYSSTATISTICS, false otherwise.

Throws:

StandardException - if accessing the data dictionary fails

getIndexTemplateRow

ExecRow getIndexTemplateRow()

getCreatedConglomNumber

long getCreatedConglomNumber()

Get the conglomerate number for the conglomerate that was created by this constant action. Will return -1L if the constant action has not yet been executed. This is used for updating conglomerate descriptors which share a conglomerate that has been dropped, in which case those "sharing" descriptors need to point to the newly-created conglomerate (the newly-created conglomerate replaces the dropped one).

getReplacedConglomNumber

long getReplacedConglomNumber()

If the purpose of this constant action was to "replace" a dropped physical conglomerate, then this method returns the conglomerate number of the dropped conglomerate. Otherwise this method will end up returning -1.

getCreatedUUID

UUID getCreatedUUID()

Get the UUID for the conglomerate descriptor that was created (or re-used) by this constant action.

loadSorter

private RowLocationRetRowSource loadSorter(ExecRow[] baseRows,
                                           ExecIndexRow[] indexRows,
                                           TransactionController tc,
                                           GroupFetchScanController scan,
                                           long sortId,
                                           RowLocation[] rl)
                                    throws StandardException

Scan the base conglomerate and insert the keys into a sorter, returning a rowSource on the sorter.

Returns:

RowSource on the sorted index keys.

Throws:

StandardException - thrown on error