org.apache.derby.impl.tools.planexporter
Class AccessDatabase

java.lang.Object
  org.apache.derby.impl.tools.planexporter.AccessDatabase

public class AccessDatabase
extends java.lang.Object

This class will perform the database connection establishment, querying the database, shut downing the database. Created under DERBY-4587-PlanExporter tool

Field Summary

private java.sql.Connection	conn
private TreeNode[]	data
private int	depth
private static int	ID
private static int	INPUT_ROWS
private static int	NEXT_QUALIFIERS
private static int	NO_OF_OPENS
private static int	NO_OF_OUTPUT_ROWS_BY_SORTER
private static int	NODE_TYPE
private static int	P_ID
private java.lang.String	query
private static int	RETURNED_ROWS
private static int	SCAN_QUALIFIERS
private static int	SCAN_TYPE
private static int	SCANNED_OBJECT
private java.lang.String	schema
private boolean	schemaExists
private static int	SORT_TYPE
private static int	VISITED_PAGES
private java.lang.String	xmlDetails

Constructor Summary

AccessDatabase(java.sql.Connection aConn, java.lang.String aSchema, java.lang.String aQuery)

AccessDatabase(java.lang.String dburl, java.lang.String aSchema, java.lang.String aQuery)

Method Summary

void	closeConnection() closing the connection to the database
private static java.sql.Connection	createConnection(java.lang.String dbURL)
private void	createXMLData(java.lang.String qry, int x) Create XML data based on the query that's passed in.
void	createXMLFragment() This method creates the queries such that after execution of the query it will return XML data fragments.
private static java.lang.String	escapeForXML(java.lang.String text) Escape characters that have a special meaning in XML.
private java.lang.String	escapeInAttribute(java.lang.String text) This method is needed since in the case of XML attributes we have to filter the quotation (") marks that is compulsory.
private void	findChildren(int idx, int dep)
private void	getChildren(int currentLevel, java.lang.String id)
TreeNode[]	getData()
int	getDepth()
java.lang.String	getQuery()
java.lang.String	getXmlString() Generating the XML tree
java.lang.String	indent(int j)
boolean	initializeDataArray()
void	markTheDepth() marking the depth of each element
private int	noOfNodes()
private boolean	schemaExists() Check if there is a schema in the database that matches the schema name that was passed in to this instance.
private void	setSchema() Set the schema of the current connection to the XPLAIN schema in which the statistics can be found.
java.lang.String	statement()
java.lang.String	stmtID()
java.lang.String	time()
boolean	verifySchemaExistance()

Methods inherited from class java.lang.Object

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

Field Detail

conn

private final java.sql.Connection conn

schema

private final java.lang.String schema

query

private final java.lang.String query

schemaExists

private final boolean schemaExists

data

private TreeNode[] data

depth

private int depth

xmlDetails

private java.lang.String xmlDetails

ID

private static final int ID

See Also:

Constant Field Values

P_ID

private static final int P_ID

See Also:

Constant Field Values

NODE_TYPE

private static final int NODE_TYPE

See Also:

Constant Field Values

NO_OF_OPENS

private static final int NO_OF_OPENS

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Constant Field Values

INPUT_ROWS

private static final int INPUT_ROWS

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Constant Field Values

RETURNED_ROWS

private static final int RETURNED_ROWS

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Constant Field Values

VISITED_PAGES

private static final int VISITED_PAGES

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Constant Field Values

SCAN_QUALIFIERS

private static final int SCAN_QUALIFIERS

See Also:

Constant Field Values

NEXT_QUALIFIERS

private static final int NEXT_QUALIFIERS

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Constant Field Values

SCANNED_OBJECT

private static final int SCANNED_OBJECT

See Also:

Constant Field Values

SCAN_TYPE

private static final int SCAN_TYPE

See Also:

Constant Field Values

SORT_TYPE

private static final int SORT_TYPE

See Also:

Constant Field Values

NO_OF_OUTPUT_ROWS_BY_SORTER

private static final int NO_OF_OUTPUT_ROWS_BY_SORTER

See Also:

Constant Field Values

Constructor Detail

AccessDatabase

public AccessDatabase(java.lang.String dburl,
                      java.lang.String aSchema,
                      java.lang.String aQuery)
               throws java.lang.InstantiationException,
                      java.lang.IllegalAccessException,
                      java.lang.ClassNotFoundException,
                      java.sql.SQLException

Parameters:

dburl -

aSchema -

aQuery -

Throws:

java.lang.InstantiationException

java.lang.IllegalAccessException

java.lang.ClassNotFoundException

java.sql.SQLException

AccessDatabase

public AccessDatabase(java.sql.Connection aConn,
                      java.lang.String aSchema,
                      java.lang.String aQuery)
               throws java.sql.SQLException

Parameters:

aConn -

aSchema -

aQuery -

Throws:

java.sql.SQLException

Method Detail

getQuery

public java.lang.String getQuery()

Returns:

the stmt_id

getDepth

public int getDepth()

createConnection

private static java.sql.Connection createConnection(java.lang.String dbURL)
                                             throws java.lang.InstantiationException,
                                                    java.lang.IllegalAccessException,
                                                    java.lang.ClassNotFoundException,
                                                    java.sql.SQLException

Throws:

java.lang.InstantiationException

java.lang.IllegalAccessException

java.lang.ClassNotFoundException

java.sql.SQLException

setSchema

private void setSchema()
                throws java.sql.SQLException

Set the schema of the current connection to the XPLAIN schema in which the statistics can be found.

Throws:

java.sql.SQLException - if an error happens while accessing the database

schemaExists

private boolean schemaExists()
                      throws java.sql.SQLException

Check if there is a schema in the database that matches the schema name that was passed in to this instance.

Throws:

java.sql.SQLException

verifySchemaExistance

public boolean verifySchemaExistance()

createXMLFragment

public void createXMLFragment()
                       throws java.sql.SQLException

This method creates the queries such that after execution of the query it will return XML data fragments.

Throws:

java.sql.SQLException

getXmlString

public java.lang.String getXmlString()

Generating the XML tree

Returns:

all xml elements as a String

getChildren

private void getChildren(int currentLevel,
                         java.lang.String id)

Parameters:

currentLevel - level of the XML tree (0 based) of current node

id - current node's stmt_id

indent

public java.lang.String indent(int j)

Parameters:

j - indent needed

Returns:

indent as a string

markTheDepth

public void markTheDepth()

marking the depth of each element

findChildren

private void findChildren(int idx,
                          int dep)

Parameters:

idx - current element's index

dep - current examining depth

initializeDataArray

public boolean initializeDataArray()
                            throws java.sql.SQLException

Returns:

whether the initialization is successful or not

Throws:

java.sql.SQLException

createXMLData

private void createXMLData(java.lang.String qry,
                           int x)
                    throws java.sql.SQLException

Create XML data based on the query that's passed in. The query should have exactly one parameter, which will be initialized to the statement id before the query is executed.

Parameters:

qry - query to be executed

Throws:

java.sql.SQLException

noOfNodes

private int noOfNodes()
               throws java.sql.SQLException

Returns:

total # of nodes

Throws:

java.sql.SQLException

statement

public java.lang.String statement()
                           throws java.sql.SQLException

Returns:

the <statement> element

Throws:

java.sql.SQLException

escapeForXML

private static java.lang.String escapeForXML(java.lang.String text)

Escape characters that have a special meaning in XML.

Parameters:

text - the text to escape

Returns:

the text with special characters escaped

escapeInAttribute

private java.lang.String escapeInAttribute(java.lang.String text)

This method is needed since in the case of XML attributes we have to filter the quotation (") marks that is compulsory. eg: scanned_object="A "quoted" table name";

Parameters:

text - attribute string to be checked

Returns:

modified string

time

public java.lang.String time()
                      throws java.sql.SQLException

Returns:

XPLAIN_TIME of SYSXPLAIN_STATEMENTS

Throws:

java.sql.SQLException

stmtID

public java.lang.String stmtID()

Returns:

stmt_id as a XML element

closeConnection

public void closeConnection()

closing the connection to the database

getData

public TreeNode[] getData()

Returns:

data array of TreeNode Objects