Class XPLAINUtil

java.lang.Object

org.apache.derby.impl.sql.execute.xplain.XPLAINUtil

public class XPLAINUtil
extends Object

This class contains helper methods, which support the System Table Visitor.

Field Summary

Fields

Modifier and Type	Field	Description
static final String	CALL_STMT_TYPE
static final String	DDL_STMT_TYPE
static final String	DELETE_STMT_TYPE
static final String	INSERT_STMT_TYPE
static final String	ISOLATION_READ_COMMIT
static final String	ISOLATION_READ_UNCOMMITED	isolation level codes
static final String	ISOLATION_REPEAT_READ
static final String	ISOLATION_SERIALIZABLE
static final String	LOCK_GRANULARITY_ROW
static final String	LOCK_GRANULARITY_TABLE	lock granularity
static final String	LOCK_MODE_EXCLUSIVE	lock modes
static final String	LOCK_MODE_INSTANTENOUS_EXCLUSIVE
static final String	LOCK_MODE_INSTANTENOUS_SHARE
static final String	LOCK_MODE_SHARE
static final String	NO_CODE
static final String	OP_AGGREGATE
static final String	OP_ANY
static final String	OP_BULK
static final String	OP_CASCADE
static final String	OP_CONSTRAINTSCAN
static final String	OP_CURRENT_OF
static final String	OP_DELETE
static final String	OP_DISTINCT
static final String	OP_DISTINCTSCAN
static final String	OP_FILTER
static final String	OP_GROUP
static final String	OP_HASHSCAN
static final String	OP_HASHTABLE
static final String	OP_INDEXSCAN
static final String	OP_INSERT
static final String	OP_JOIN_HASH
static final String	OP_JOIN_HASH_LO
static final String	OP_JOIN_NL
static final String	OP_JOIN_NL_LO
static final String	OP_LASTINDEXKEYSCAN
static final String	OP_MATERIALIZE
static final String	OP_NORMALIZE
static final String	OP_ONCE
static final String	OP_PROJ_RESTRICT
static final String	OP_PROJECT
static final String	OP_ROW
static final String	OP_ROW_COUNT
static final String	OP_ROWIDSCAN
static final String	OP_SCROLL
static final String	OP_SET
static final String	OP_SET_EXCEPT
static final String	OP_SET_INTERSECT
static final String	OP_SORT
static final String	OP_TABLESCAN	the rs operator codes
static final String	OP_UNION
static final String	OP_UPDATE
static final String	OP_VTI
static final String	OP_VTI_RS
static final String	OP_WINDOW
static final String	SCAN_BITSET_ALL
static final String	SCAN_BTREE
static final String	SCAN_HEAP	the scan info codes
static final String	SCAN_SORT
static final String	SELECT_APPROXIMATE_STMT_TYPE
static final String	SELECT_STMT_TYPE	the different statement type constants
static final String	SORT_EXTERNAL	sort info properties
static final String	SORT_INTERNAL
static final String	UPDATE_STMT_TYPE
static final String	XPLAIN_FULL
static final String	XPLAIN_ONLY	the explain type constants
static final String	YES_CODE	yes no codes

Constructor Summary

Constructors

Constructor	Description
XPLAINUtil()

Method Summary

Modifier and Type	Method	Description
static XPLAINScanPropsDescriptor	extractScanProps(XPLAINScanPropsDescriptor descriptor, Properties scanProps)	helper method which extracts the right (non-internationalzed) scan properties of the scan info properties
static XPLAINSortPropsDescriptor	extractSortProps(XPLAINSortPropsDescriptor descriptor, Properties sortProps)	helper method which extracts the right (non-internationalzed) sort properties of the sort info properties object
static Long	getAVGNextTime(long dividend, long divisor)	Compute average, avoiding divide-by-zero problems.
static String	getHashKeyColumnNumberString(int[] hashKeyColumns)
static String	getIsolationLevelCode(String isolationLevel)	util function, to resolve the isolation level and return a isolation level code
static String	getLockGranularityCode(String lockString)	util function, to resolve the lock granularity and return a lock granularity code
static String	getLockModeCode(String lockString)	util function, to resolve the lock mode, and return a lock mode code
static String	getStatementType(String SQLText)	This method helps to figure out the statement type and returns an appropriate return code, characterizing the stmt type.
static String	getYesNoCharFromBoolean(boolean test)

Methods inherited from class Object

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

Field Details

ISOLATION_READ_UNCOMMITED

public static final String ISOLATION_READ_UNCOMMITED

isolation level codes

See Also:

• Constant Field Values

ISOLATION_READ_COMMIT

public static final String ISOLATION_READ_COMMIT

See Also:

• Constant Field Values

ISOLATION_REPEAT_READ

public static final String ISOLATION_REPEAT_READ

See Also:

• Constant Field Values

ISOLATION_SERIALIZABLE

public static final String ISOLATION_SERIALIZABLE

See Also:

• Constant Field Values

LOCK_MODE_EXCLUSIVE

public static final String LOCK_MODE_EXCLUSIVE

lock modes

See Also:

• Constant Field Values

LOCK_MODE_INSTANTENOUS_EXCLUSIVE

public static final String LOCK_MODE_INSTANTENOUS_EXCLUSIVE

See Also:

• Constant Field Values

LOCK_MODE_SHARE

public static final String LOCK_MODE_SHARE

See Also:

• Constant Field Values

LOCK_MODE_INSTANTENOUS_SHARE

public static final String LOCK_MODE_INSTANTENOUS_SHARE

See Also:

• Constant Field Values

LOCK_GRANULARITY_TABLE

public static final String LOCK_GRANULARITY_TABLE

lock granularity

See Also:

• Constant Field Values

LOCK_GRANULARITY_ROW

public static final String LOCK_GRANULARITY_ROW

See Also:

• Constant Field Values

OP_TABLESCAN

public static final String OP_TABLESCAN

the rs operator codes

See Also:

• Constant Field Values

OP_INDEXSCAN

public static final String OP_INDEXSCAN

See Also:

• Constant Field Values

OP_HASHSCAN

public static final String OP_HASHSCAN

See Also:

• Constant Field Values

OP_DISTINCTSCAN

public static final String OP_DISTINCTSCAN

See Also:

• Constant Field Values

OP_LASTINDEXKEYSCAN

public static final String OP_LASTINDEXKEYSCAN

See Also:

• Constant Field Values

OP_HASHTABLE

public static final String OP_HASHTABLE

See Also:

• Constant Field Values

OP_ROWIDSCAN

public static final String OP_ROWIDSCAN

See Also:

• Constant Field Values

OP_CONSTRAINTSCAN

public static final String OP_CONSTRAINTSCAN

See Also:

• Constant Field Values

OP_JOIN_NL

public static final String OP_JOIN_NL

See Also:

• Constant Field Values

OP_JOIN_HASH

public static final String OP_JOIN_HASH

See Also:

• Constant Field Values

OP_JOIN_NL_LO

public static final String OP_JOIN_NL_LO

See Also:

• Constant Field Values

OP_JOIN_HASH_LO

public static final String OP_JOIN_HASH_LO

See Also:

• Constant Field Values

OP_UNION

public static final String OP_UNION

See Also:

• Constant Field Values

OP_SET

public static final String OP_SET

See Also:

• Constant Field Values

OP_SET_INTERSECT

public static final String OP_SET_INTERSECT

See Also:

• Constant Field Values

OP_SET_EXCEPT

public static final String OP_SET_EXCEPT

See Also:

• Constant Field Values

OP_INSERT

public static final String OP_INSERT

See Also:

• Constant Field Values

OP_UPDATE

public static final String OP_UPDATE

See Also:

• Constant Field Values

OP_DELETE

public static final String OP_DELETE

See Also:

• Constant Field Values

OP_CASCADE

public static final String OP_CASCADE

See Also:

• Constant Field Values

OP_VTI

public static final String OP_VTI

See Also:

• Constant Field Values

OP_BULK

public static final String OP_BULK

See Also:

• Constant Field Values

OP_DISTINCT

public static final String OP_DISTINCT

See Also:

• Constant Field Values

OP_NORMALIZE

public static final String OP_NORMALIZE

See Also:

• Constant Field Values

OP_ANY

public static final String OP_ANY

See Also:

• Constant Field Values

OP_SCROLL

public static final String OP_SCROLL

See Also:

• Constant Field Values

OP_MATERIALIZE

public static final String OP_MATERIALIZE

See Also:

• Constant Field Values

OP_ONCE

public static final String OP_ONCE

See Also:

• Constant Field Values

OP_VTI_RS

public static final String OP_VTI_RS

See Also:

• Constant Field Values

OP_ROW

public static final String OP_ROW

See Also:

• Constant Field Values

OP_PROJECT

public static final String OP_PROJECT

See Also:

• Constant Field Values

OP_FILTER

public static final String OP_FILTER

See Also:

• Constant Field Values

OP_AGGREGATE

public static final String OP_AGGREGATE

See Also:

• Constant Field Values

OP_PROJ_RESTRICT

public static final String OP_PROJ_RESTRICT

See Also:

• Constant Field Values

OP_SORT

public static final String OP_SORT

See Also:

• Constant Field Values

OP_GROUP

public static final String OP_GROUP

See Also:

• Constant Field Values

OP_CURRENT_OF

public static final String OP_CURRENT_OF

See Also:

• Constant Field Values

OP_ROW_COUNT

public static final String OP_ROW_COUNT

See Also:

• Constant Field Values

OP_WINDOW

public static final String OP_WINDOW

See Also:

• Constant Field Values

SCAN_HEAP

public static final String SCAN_HEAP

the scan info codes

See Also:

• Constant Field Values

SCAN_BTREE

public static final String SCAN_BTREE

See Also:

• Constant Field Values

SCAN_SORT

public static final String SCAN_SORT

See Also:

• Constant Field Values

SCAN_BITSET_ALL

public static final String SCAN_BITSET_ALL

See Also:

• Constant Field Values

SELECT_STMT_TYPE

public static final String SELECT_STMT_TYPE

the different statement type constants

See Also:

• Constant Field Values

SELECT_APPROXIMATE_STMT_TYPE

public static final String SELECT_APPROXIMATE_STMT_TYPE

See Also:

• Constant Field Values

INSERT_STMT_TYPE

public static final String INSERT_STMT_TYPE

See Also:

• Constant Field Values

UPDATE_STMT_TYPE

public static final String UPDATE_STMT_TYPE

See Also:

• Constant Field Values

DELETE_STMT_TYPE

public static final String DELETE_STMT_TYPE

See Also:

• Constant Field Values

CALL_STMT_TYPE

public static final String CALL_STMT_TYPE

See Also:

• Constant Field Values

DDL_STMT_TYPE

public static final String DDL_STMT_TYPE

See Also:

• Constant Field Values

XPLAIN_ONLY

public static final String XPLAIN_ONLY

the explain type constants

See Also:

• Constant Field Values

XPLAIN_FULL

public static final String XPLAIN_FULL

See Also:

• Constant Field Values

SORT_EXTERNAL

public static final String SORT_EXTERNAL

sort info properties

See Also:

• Constant Field Values

SORT_INTERNAL

public static final String SORT_INTERNAL

See Also:

• Constant Field Values

YES_CODE

public static final String YES_CODE

yes no codes

See Also:

• Constant Field Values

NO_CODE

public static final String NO_CODE

See Also:

• Constant Field Values

Constructor Details

XPLAINUtil

public XPLAINUtil()

Method Details

getYesNoCharFromBoolean

public static String getYesNoCharFromBoolean(boolean test)

getHashKeyColumnNumberString

public static String getHashKeyColumnNumberString(int[] hashKeyColumns)

getLockModeCode

public static String getLockModeCode(String lockString)

util function, to resolve the lock mode, and return a lock mode code

getIsolationLevelCode

public static String getIsolationLevelCode(String isolationLevel)

util function, to resolve the isolation level and return a isolation level code

getLockGranularityCode

public static String getLockGranularityCode(String lockString)

util function, to resolve the lock granularity and return a lock granularity code

getStatementType

public static String getStatementType(String SQLText)

This method helps to figure out the statement type and returns an appropriate return code, characterizing the stmt type.

extractScanProps

public static XPLAINScanPropsDescriptor extractScanProps(XPLAINScanPropsDescriptor descriptor,
 Properties scanProps)

helper method which extracts the right (non-internationalzed) scan properties of the scan info properties

Parameters:

descriptor - the descriptor to fill with properties

scanProps - the provided scan props

Returns:

the filled descriptor

extractSortProps

public static XPLAINSortPropsDescriptor extractSortProps(XPLAINSortPropsDescriptor descriptor,
 Properties sortProps)

helper method which extracts the right (non-internationalzed) sort properties of the sort info properties object

Parameters:

descriptor - the descriptor to fill with properties

sortProps - the provided sort props

Returns:

the filled descriptor

getAVGNextTime

public static Long getAVGNextTime(long dividend,
 long divisor)

Compute average, avoiding divide-by-zero problems.

Parameters:

dividend - the long value for the dividend (the whole next time)

divisor - the long value for the divisor (the sum of all rows seen)

Returns:

the quotient or null