Java and Berkeley XML DB

Hi,
I read that Berkeley XML DB is an XML database which uses the Berkeley DB as the actual storage engine.
Berkeley DB itself is available as a binary in either C/C++ or as a 100% Java lib which can nicely be used via maven.
Now I had thought, that there is also a 100% Java version of Berkeley XML DB which just sits on top of the Berkeley DB Java version as its backend. Instead it seems that the Java API to the XML DB is actually using the C/C++ Version of Berkeley DB via JNI calls.
Is that correct?
Günther

Günther,
Sorry this post was unanswered for so long. You're understanding is correct -- Berkeley DB XML's core is written in C++ and uses the Berkeley DB C engine for storage. The Java API for Berkeley DB XML is implemented on the C++ code using JNI.
There is no 100% Java version of Berkeley DB XML.
George

Similar Messages

Compatibility issues between Berkeley DB Java Edition and Berkeley DB

We are trying to use both Berkeley DB Java Edition and Berkeley DB (Java/C) in one of our projects. However, they share the common classes (i.e. EntryDingin.java), but with their own different impementation. Is there any reason that they have to share the same names/packages? Can we request to have the shared java classes going into different packages?
Thanks
Yao

Hello Yao,
You're correct and the DB and JE products were not designed to run under the same classloader in the same JVM. It is very unlikely that we'll be changing the package names, since that would be very disruptive and yet have no value for the overwhelming majority of users. We will note your request, however, for future reference.
The two workarounds I know of are:
1. Use a separate classloader for the use of each product.
2. Use a tool such as jarjar links (http://code.google.com/p/jarjar/) to rename the packages in one or both of the products.
Option 2 is not something we (the JE team members) have experience with, but it was used successfully by a JE user. The user also pointed out a bug in the jarjar tool to be aware of: http://code.google.com/p/jarjar/issues/detail?id=21
--mark

Question about Java and XML rendering for Word 97 upwards.

Without using the apache POI library, and by sticking to non-pay products,
is it possible to use java or XSLT/XML to turn
an xml formatted file into a
Microsoft Word/Excell/PDF file within one framework?

Look into Apache FOP. But be warned: it will most likely use POI to do any excel conversions. That's how (sane) software development works: you don't reinvent the wheel, you effectively reuse what is already there.

Can somebody explain to me how java and xml are related?

Hi guys
im new to java and xml.Been reading a lot regarding java and don't seem to have a problem with it...
the problem is the xml part...im doing a simple GUI project using swing(online store) and i have to convert it to xml
I have absolutely NO IDEA why i must convert my java to xml and have no idea how to do that.I been reading on the net that xml is a exten~ markup language and it is better and useful.
Can somebody explain to me in layman terms
1)how is java and xml related in?
2)why do ppl want to convert java to xml when they can just stick to java
3)what is actually xml...
4)Do i need a program to create xml like i need jcreater to create java application
5)How do we actually convert?is there any links that you guys could tell me?
thank you
tomleo

im new to java and xml.Been reading a lot regarding
java and don't seem to have a problem with it...Okay.
the problem is the xml part...im doing a simple GUI
project using swing(online store) and i have to
o convert it to xmlYou have to? So presumably somebody in a position of authority told you that?
I have absolutely NO IDEA why i must convert my java
to xml and have no idea how to do that.I been reading
on the net that xml is a exten~ markup language and
it is better and useful.I have no idea either (besides which, it doesn't make sense). But why ask us? Somebody told you to do that, ask them why.
Sure, XML is useful. But it isn't a programming language so it can't be used as a substitute for Java.
Can somebody explain to me in layman terms
1)how is java and xml related in?They aren't related, except perhaps in that they are both used in computers.
2)why do ppl want to convert java to xml when they
can just stick to javaThey don't.
3)what is actually xml...Start here for numerous definitions:
http://www.google.ca/search?hl=en&lr=&oi=defmore&q=define:XML
4)Do i need a program to create xml like i need
jcreater to create java applicationNo, XML is just text. But then Java code is just text too.
5)How do we actually convert?is there any links that
you guys could tell me?You don't convert Java to XML. My guess is that because you don't know much about Java or XML, you have misinterpreted something that somebody told you.

Urgent help(xml, java and asp)

Hi all,
I,m new with XML and i have to convert a VB application that connects to an ASP using Microsoft XML and I need to know if I can connect from a java application to an ASP using XML for transfering the infornation.
In the ASP side it uses DOM, and I would like not to touch the ASP and create a new application with java and get rid of the VB application

DrClap what I have in the VB side is this:
Private Function SetBalanceForReal(Amount As Currency, Action As String) As Boolean
On Error GoTo ehSetBalance
Dim ohttp As New MSXML.XMLHTTPRequest
Dim oResponseXML As New MSXML.DOMDocument
Dim oDoc As New MSXML.XMLDSOControl
Dim oElement As MSXML.IXMLDOMElement
Dim oNode As MSXML.IXMLDOMNode
ohttp.open "POST", ServerUrl & "ActualizaBalance.asp", False
Set oElement = oDoc.XMLDocument.createElement("ActualizaBalance")
Set oNode = oElement.appendChild(oDoc.XMLDocument.createNode(1, "Client", ""))
Set oNode = oElement.appendChild(oDoc.XMLDocument.createNode(1, "Action", ""))
Set oNode = oElement.appendChild(oDoc.XMLDocument.createNode(1, "Amount", ""))
oElement.childNodes.Item(0).Text = Trim(ClientLogin)
oElement.childNodes.Item(1).Text = Action
oElement.childNodes.Item(2).Text = Amount
ohttp.send (oElement.xml)
oResponseXML.loadXML (ohttp.responseText)
If oResponseXML.documentElement.childNodes.Item(1).Text = "OK" Then
Available = oResponseXML.documentElement.childNodes.Item(0).Text
Else
Available = 0
End If
Set ohttp = Nothing
Set oResponseXML = Nothing
Set oDoc = Nothing
Set oElement = Nothing
Set oNode = Nothing
SetBalanceForReal = True
Exit Function
ehSetBalance:
Set oNode = Nothing
Set oElement = Nothing
Set oDoc = Nothing
Set oResponseXML = Nothing
Set ohttp = Nothing
Available = 0
SetBalanceForReal = False
End Function
Public Function GetConsecutive(Game As String) As Boolean
On Error GoTo ehGetConsecutive
Dim ohttp As New MSXML.XMLHTTPRequest
Dim oResponseXML As New MSXML.DOMDocument
Dim oDoc As New MSXML.XMLDSOControl
Dim oElement As MSXML.IXMLDOMElement
Dim oNode As MSXML.IXMLDOMNode
ohttp.open "POST", ServerUrl & "ObtieneConsecutivo.asp", False
Set oElement = oDoc.XMLDocument.createElement("ObtieneConsecutivo")
Set oNode = oElement.appendChild(oDoc.XMLDocument.createNode(1, "Game", ""))
oElement.childNodes.Item(0).Text = Game
ohttp.send (oElement.xml)
oResponseXML.loadXML (ohttp.responseText)
Consecutive = oResponseXML.documentElement.childNodes.Item(0).Text
Set ohttp = Nothing
Set oResponseXML = Nothing
Set oDoc = Nothing
Set oElement = Nothing
Set oNode = Nothing
GetConsecutive = True
Exit Function
ehGetConsecutive:
Set oNode = Nothing
Set oElement = Nothing
Set oDoc = Nothing
Set oResponseXML = Nothing
Set ohttp = Nothing
Consecutive = 0
GetConsecutive = False
End Function
and the ASP code is this:
<%@LANGUAGE=VBScript%>
<%
     'Variables Simples
     Dim Cliente
     Dim Accion
     Dim Monto
     'Variables Complejas
     Dim oClienteBD
     Dim oClienteInfoXML
     Dim oDoc
     Dim oElemento
     Dim oNode
     'Inicializacion de Variables Complejas
     Set oClienteBD = Server.CreateObject("Casino_Clases.CClient")
     Set oClientInfoXML = Server.CreateObject("MSXML.DOMDocument")
     Set oDoc          = Server.CreateObject("MSXML2.DSOControl")
     oClientInfoXML.async=false
     oClientInfoXML.load(Request)
     Cliente = oClientInfoXML.documentElement.childNodes.item(0).text
     Accion = oClientInfoXML.documentElement.childNodes.item(1).text
     Monto = oClientInfoXML.documentElement.childNodes.item(2).text
     Set oElemento = oDoc.XMLDocument.createElement("Resultado")
     Set oNode = oElemento.appendChild(oDoc.XMLDocument.createNode(1, "AVAILABLE",""))
     Set oNode = oElemento.appendChild(oDoc.XMLDocument.createNode(1, "ESTADO",""))
     If oClienteBD.UpdateBalance(Cliente, Accion, Monto) = True Then
          If oClienteBD.GetClientBalance(Cliente) = True Then
               oElemento.childNodes.Item(0).Text = oClienteBD.Available
               oElemento.childNodes.Item(1).Text = "OK"
          else
               oElemento.childNodes.Item(0).Text = 0
               oElemento.childNodes.Item(1).Text = "BAD"
          end If
     else
          oElemento.childNodes.Item(0).Text = 0
          oElemento.childNodes.Item(1).Text = "BAD"
     end If
     Response.Write(oElemento.xml)
     Set oClientInfoXML = Nothing
     Set oDoc = Nothing
     Set oClienteBD = Nothing
     Set oNode          = Nothing
     Set oElemento     = Nothing
%>
What I need to do is to change the VB part for a Java application and basicly, I don't know what Class of Java I have to use to connect to the ASP.
If you were so kind of giving me an example to do this I will appreciate it.
Ocorella

How to read and write XML in java

I have a code that reads a large XML file, splits it into smaller files, filters and then writes it into a new XML file. My problem is that I had coded the input file name into the code, so that only the specified file can be read. How can I rewrite my code to be able to take any input xml and perform the same operation? Here's a portion of my code below:
                        File file = new File("c:\\APAdjustmentJVDoc_FINAL.xml");
                    output = new BufferedWriter(new FileWriter(file));
                    for (int i = 1; i < 79; i++) {
                         fIStream = new FileInputStream("c:\\APAdjustmentJVDoc_new" + i + ".xml");
                         loRead = new InputStreamReader(fIStream);
                         doc = XMLUtil.transformToNode(loRead, false);
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                         writeFile(doc, docIdList, output);
                         fIStream.close();
                         loRead.close();
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You need to pass your filename String as a parameter to your functionality. It depends how you're currently set up though. We can't really see the top of your call so it's difficult to determine what you are calling and we don't really know from where you're calling either.
If you're running standalone, then on launch of the application, you can feed in a file name as an argument that you can read in in String args[] in the main function and pass down to your XML splitter.
If you're a method in a class that's part of a bigger pile, you can feed the file name as a String to the method from wherever you call from if it makes sense architecturally.
You might also want to pass down a File object if that makes sense in your current code (i.e. if you're using your file for other purposes prior to the split, to avoid recreating closing/opening for no reason).
Depends what you're trying to do. If I put together a piece like this, I would probably create an <yourcurrentrootpackage>.xml.splitter package.
Also, on a side note, you're problem isn't really reading and writing XML in java, but seems more to be making your functionality generic so that any XML file can be split with your code.
Regards
JFM

Getting started with Java and XML

Hi,
Although I am pretty familiar with Java, I am a total newbie with using it to parse XML. I have been reading quite a few tutorials so am getting a good understanding of it and am thinking of using the DOM model for my purposes.
What I haven't been able to find, however, is how I can actually get started with this. I have tried compiling a few examples and have been getting errors such as:
xmltest.java package javax.xml.parsers does not exist
xmltest.java package org.w3c.dom does not existetc etc...
It looks like these packages don't come with J2SE. Can anyone confirm this? Do I need to download and install the Java Web Services Developer Pack to solve this problem?
Finally, I know I will need an XML parser but have read that JDK 1.4 has it's own parser (Crimson). Is this adequate for parsing XML files or will I also need a parser such as Xerces?
Thanks so much for any help!

Hi DrClap,
Thanks for the reply. I have JDK 1.4.1_02 installed on my server but the following error keeps coming up when I try to run my example:
Exception in thread "main" java.lang.NoClassDefFoundError: org/w3c/dom/NodeAre there any further packages I need to download in order to run Java with XML? I have read some people install JAXP and XERCES... are these necessary for parsing an XML document or should J2SE 1.4.1 be sufficient?
Thanks for your help!
Jill

Java XML-Reader (SAX)--How to read and display xml-element-data???

hello all,
i would like to display just some xml-data
Which methods in java should i use to select just one character-data of this (for example: "deu" from the element <Language> or the attribut "version" of the element <catalog>).
Here is the XML-document i want to parse and display it with System.out.print() :
<BMECAT version="1.2">
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               e-proCat 2.1, e-pro solutions GmbH
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</HEADER>
</BMECAT>
Here is the java application i wrote and which doesn t work:
import org.apache.xerces.parsers.SAXParser;
import org.xml.sax.Attributes;
import org.xml.sax.ContentHandler;
import org.xml.sax.Locator;
import org.xml.sax.SAXException;
import org.xml.sax.XMLReader;
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public XmlLeser(String fileName) {
try {
XMLReader myParser = new SAXParser(); // SAXParser (Xerces)
myParser.setContentHandler(this);
myParser.parse(fileName);      } catch (Exception e) {
     System.out.println("Erreur " + e);     }
}// End of constructor
public void startDocument() {
     System.out.println(" start to parse " );
} // startDocument()
public void endDocument() {
System.out.println(" End of Parse ");
} // endDocument()
public void startElement(String namespaceURI, String localName, String qName, Attributes atts) throws SAXException {
     System.out.println(localName) ;
public void endElement(String namespaceURI, String localName, String qName) throws SAXException {
}// Endelement()
public void characters(char ch[], int start, int length) {
} // endCharacters(char[],int,int);
public void processingInstruction(String target, String data) {
} // processingInstruction(String,String)
public void ignorableWhitespace(char ch[], int start, int length) {
          characters(ch, start, length);
} // ignorableWhitespace(char[],int,int);
public static void main(String args[]) {
String xmlFileName = "";
if (args.length == 0) {
System.out.println("Usage::java XmlLeser path/xmlFilename");
System.exit(0);      } else {
xmlFileName = args[0];
XmlLeser pux = new XmlLeser(xmlFileName);
}// end main()
}//endClass

You need to pass your filename String as a parameter to your functionality. It depends how you're currently set up though. We can't really see the top of your call so it's difficult to determine what you are calling and we don't really know from where you're calling either.
If you're running standalone, then on launch of the application, you can feed in a file name as an argument that you can read in in String args[] in the main function and pass down to your XML splitter.
If you're a method in a class that's part of a bigger pile, you can feed the file name as a String to the method from wherever you call from if it makes sense architecturally.
You might also want to pass down a File object if that makes sense in your current code (i.e. if you're using your file for other purposes prior to the split, to avoid recreating closing/opening for no reason).
Depends what you're trying to do. If I put together a piece like this, I would probably create an <yourcurrentrootpackage>.xml.splitter package.
Also, on a side note, you're problem isn't really reading and writing XML in java, but seems more to be making your functionality generic so that any XML file can be split with your code.
Regards
JFM

Java and XML How to

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I have seen that can someone give me a project or some place that explains it Better ?

Java and XML or XHTML Journey Planner Project

Hello chaps,
I need some help with a project I am doing.
This project will be focusing on the area of information visualisation and the phenomena surrounding how data can be optimised in a confined space. Expanding on this, confined space can be a mobile phone screen, and personal organisers where information is shown in a limited area.
I plan to use Java and XML. (or XHTML)
I want to have a running application where raw data is transformed into a combination of graphics and information. To achieve this, I will be looking at route planning for mobile phones and how route instructions can be represented in a visual but a sophisticated way.
My focus will be on the London transport.
Here is a link to the London transport journey planner
http://www.tfl.gov.uk/journeyplanner
Using WAP, I surfed the website on my phone and there seems to be a lot of writing and there is a lot to process before understanding what is going on. I want to transform words into pictures e.g., the word underground or bus into a logo of a red bus or underground logo or Instead of ?walk?, a picture of a walking pedestrian. Picture are good connotations as we can easily recognise rather than processing words. I would also like to represent the time taken in a graph format, again, to easily visualise.
The application can be on a phone or on Windows simulating a mobile phone.
Can anyone help me with this mammoth task or at least point me out in the correct direction?
Looking forward to your reply.

1st, ) Raw Data e.g, journey time, journey distance
2nd, ) I would want the system to recognise the 'raw data' mentioned before and transform this into graphical image(s).
3rd ) a complete visualisation would look like,
modes of transport represented by pics or logos, showing the time to get to from A to B.
Showing various routes, eg, walking, and/or bus and/or tube

Java and xml option necessary?

Hi,
first when i build the repository database, i choose java and xml option, is this necessary or i waste my time.
When i read Building a Help Desk Connector, i'm not sure, do i need the Diagnostic Pack.
Best regards
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This is the defacto site for xpath stuff for java
http://xml.apache.org/xalan-j/

Java and XML Doc

I am new to Java and XML, I want to know the steps i should follow to work with XML document using XPATH. also the APIs and Technologies i shoud work. If possible guide me any examples or tutorials for that.

This is the defacto site for xpath stuff for java
http://xml.apache.org/xalan-j/

Need help with Berkeley XML DB Performance

We need help with maximizing performance of our use of Berkeley XML DB. I am filling most of the 29 part question as listed by Oracle's BDB team.
Berkeley DB XML Performance Questionnaire
1. Describe the Performance area that you are measuring? What is the
current performance? What are your performance goals you hope to
achieve?
We are measuring the performance while loading a document during
web application startup. It is currently taking 10-12 seconds when
only one user is on the system. We are trying to do some testing to
get the load time when several users are on the system.
We would like the load time to be 5 seconds or less.
2. What Berkeley DB XML Version? Any optional configuration flags
specified? Are you running with any special patches? Please specify?
dbxml 2.4.13. No special patches.
3. What Berkeley DB Version? Any optional configuration flags
specified? Are you running with any special patches? Please Specify.
bdb 4.6.21. No special patches.
4. Processor name, speed and chipset?
Intel Xeon CPU 5150 2.66GHz
5. Operating System and Version?
Red Hat Enterprise Linux Relase 4 Update 6
6. Disk Drive Type and speed?
Don't have that information
7. File System Type? (such as EXT2, NTFS, Reiser)
EXT3
8. Physical Memory Available?
4GB
9. Are you using Replication (HA) with Berkeley DB XML? If so, please
describe the network you are using, and the number of Replica’s.
No
10. Are you using a Remote Filesystem (NFS) ? If so, for which
Berkeley DB XML/DB files?
No
11. What type of mutexes do you have configured? Did you specify
–with-mutex=? Specify what you find inn your config.log, search
for db_cv_mutex?
None. Did not specify -with-mutex during bdb compilation
12. Which API are you using (C++, Java, Perl, PHP, Python, other) ?
Which compiler and version?
Java 1.5
13. If you are using an Application Server or Web Server, please
provide the name and version?
Oracle Appication Server 10.1.3.4.0
14. Please provide your exact Environment Configuration Flags (include
anything specified in you DB_CONFIG file)
Default.
15. Please provide your Container Configuration Flags?
final EnvironmentConfig envConf = new EnvironmentConfig();
envConf.setAllowCreate(true); // If the environment does not
// exist, create it.
envConf.setInitializeCache(true); // Turn on the shared memory
// region.
envConf.setInitializeLocking(true); // Turn on the locking subsystem.
envConf.setInitializeLogging(true); // Turn on the logging subsystem.
envConf.setTransactional(true); // Turn on the transactional
// subsystem.
envConf.setLockDetectMode(LockDetectMode.MINWRITE);
envConf.setThreaded(true);
envConf.setErrorStream(System.err);
envConf.setCacheSize(1024*1024*64);
envConf.setMaxLockers(2000);
envConf.setMaxLocks(2000);
envConf.setMaxLockObjects(2000);
envConf.setTxnMaxActive(200);
envConf.setTxnWriteNoSync(true);
envConf.setMaxMutexes(40000);
16. How many XML Containers do you have? For each one please specify:
One.
1. The Container Configuration Flags
          XmlContainerConfig xmlContainerConfig = new XmlContainerConfig();
          xmlContainerConfig.setTransactional(true);
xmlContainerConfig.setIndexNodes(true);
xmlContainerConfig.setReadUncommitted(true);
2. How many documents?
Everytime the user logs in, the current xml document is loaded from
a oracle database table and put it in the Berkeley XML DB.
The documents get deleted from XML DB when the Oracle application
server container is stopped.
The number of documents should start with zero initially and it
will grow with every login.
3. What type (node or wholedoc)?
Node
4. Please indicate the minimum, maximum and average size of
documents?
The minimum is about 2MB and the maximum could 20MB. The average
mostly about 5MB.
5. Are you using document data? If so please describe how?
We are using document data only to save changes made
to the application data in a web application. The final save goes
to the relational database. Berkeley XML DB is just used to store
temporary data since going to the relational database for each change
will cause severe performance issues.
17. Please describe the shape of one of your typical documents? Please
do this by sending us a skeleton XML document.
Due to the sensitive nature of the data, I can provide XML schema instead.
18. What is the rate of document insertion/update required or
expected? Are you doing partial node updates (via XmlModify) or
replacing the document?
The document is inserted during user login. Any change made to the application
data grid or other data components gets saved in Berkeley DB. We also have
an automatic save every two minutes. The final save from the application
gets saved in a relational database.
19. What is the query rate required/expected?
Users will not be entering data rapidly. There will be lot of think time
before the users enter/modify data in the web application. This is a pilot
project but when we go live with this application, we will expect 25 users
at the same time.
20. XQuery -- supply some sample queries
1. Please provide the Query Plan
2. Are you using DBXML_INDEX_NODES?
Yes.
3. Display the indices you have defined for the specific query.
     XmlIndexSpecification spec = container.getIndexSpecification();
     // ids
     spec.addIndex("", "id", XmlIndexSpecification.PATH_NODE | XmlIndexSpecification.NODE_ATTRIBUTE | XmlIndexSpecification.KEY_EQUALITY, XmlValue.STRING);
     spec.addIndex("", "idref", XmlIndexSpecification.PATH_NODE | XmlIndexSpecification.NODE_ATTRIBUTE | XmlIndexSpecification.KEY_EQUALITY, XmlValue.STRING);
     // index to cover AttributeValue/Description
     spec.addIndex("", "Description", XmlIndexSpecification.PATH_EDGE | XmlIndexSpecification.NODE_ELEMENT | XmlIndexSpecification.KEY_SUBSTRING, XmlValue.STRING);
     // cover AttributeValue/@value
     spec.addIndex("", "value", XmlIndexSpecification.PATH_EDGE | XmlIndexSpecification.NODE_ATTRIBUTE | XmlIndexSpecification.KEY_EQUALITY, XmlValue.STRING);
     // item attribute values
     spec.addIndex("", "type", XmlIndexSpecification.PATH_EDGE | XmlIndexSpecification.NODE_ATTRIBUTE | XmlIndexSpecification.KEY_EQUALITY, XmlValue.STRING);
     // default index
     spec.addDefaultIndex(XmlIndexSpecification.PATH_NODE | XmlIndexSpecification.NODE_ELEMENT | XmlIndexSpecification.KEY_EQUALITY, XmlValue.STRING);
     spec.addDefaultIndex(XmlIndexSpecification.PATH_NODE | XmlIndexSpecification.NODE_ATTRIBUTE | XmlIndexSpecification.KEY_EQUALITY, XmlValue.STRING);
     // save the spec to the container
     XmlUpdateContext uc = xmlManager.createUpdateContext();
     container.setIndexSpecification(spec, uc);
4. If this is a large query, please consider sending a smaller
query (and query plan) that demonstrates the problem.
21. Are you running with Transactions? If so please provide any
transactions flags you specify with any API calls.
Yes. READ_UNCOMMITED in some and READ_COMMITTED in other transactions.
22. If your application is transactional, are your log files stored on
the same disk as your containers/databases?
Yes.
23. Do you use AUTO_COMMIT?
     No.
24. Please list any non-transactional operations performed?
No.
25. How many threads of control are running? How many threads in read
only mode? How many threads are updating?
We use Berkeley XML DB within the context of a struts web application.
Each user logged into the web application will be running a bdb transactoin
within the context of a struts action thread.
26. Please include a paragraph describing the performance measurements
you have made. Please specifically list any Berkeley DB operations
where the performance is currently insufficient.
We are clocking 10-12 seconds of loading a document from dbd when
five users are on the system.
getContainer().getDocument(documentName);
27. What performance level do you hope to achieve?
We would like to get less than 5 seconds when 25 users are on the system.
28. Please send us the output of the following db_stat utility commands
after your application has been running under "normal" load for some
period of time:
% db_stat -h database environment -c
% db_stat -h database environment -l
% db_stat -h database environment -m
% db_stat -h database environment -r
% db_stat -h database environment -t
(These commands require the db_stat utility access a shared database
environment. If your application has a private environment, please
remove the DB_PRIVATE flag used when the environment is created, so
you can obtain these measurements. If removing the DB_PRIVATE flag
is not possible, let us know and we can discuss alternatives with
you.)
If your application has periods of "good" and "bad" performance,
please run the above list of commands several times, during both
good and bad periods, and additionally specify the -Z flags (so
the output of each command isn't cumulative).
When possible, please run basic system performance reporting tools
during the time you are measuring the application's performance.
For example, on UNIX systems, the vmstat and iostat utilities are
good choices.
Will give this information soon.
29. Are there any other significant applications running on this
system? Are you using Berkeley DB outside of Berkeley DB XML?
Please describe the application?
No to the first two questions.
The web application is an online review of test questions. The users
login and then review the items one by one. The relational database
holds the data in xml. During application load, the application
retrieves the xml and then saves it to bdb. While the user
is making changes to the data in the application, it writes those
changes to bdb. Finally when the user hits the SAVE button, the data
gets saved to the relational database. We also have an automatic save
every two minues, which saves bdb xml data and saves it to relational
database.
Thanks,
Madhav
[email protected]

Could it be that you simply do not have set up indexes to support your query? If so, you could do some basic testing using the dbxml shell:
milu@colinux:~/xpg > dbxml -h ~/dbenv
Joined existing environment
dbxml> setverbose 7 2
dbxml> open tv.dbxml
dbxml> listIndexes
dbxml> query     { collection()[//@date-tip]/*[@chID = ('ard','zdf')] (: example :) }
dbxml> queryplan { collection()[//@date-tip]/*[@chID = ('ard','zdf')] (: example :) }Verbosity will make the engine display some (rather cryptic) information on index usage. I can't remember where the output is explained; my feeling is that "V(...)" means the index is being used (which is good), but that observation may not be accurate. Note that some details in the setVerbose command could differ, as I'm using 2.4.16 while you're using 2.4.13.
Also, take a look at the query plan. You can post it here and some people will be able to diagnose it.
Michael Ludwig

Berkeley Xml 2.4.13 works on Tomcat but not on Glassfish

I recently upgraded my web app to using the latest version of Berkeley Xml from 2.3. The old version worked fine on both glassfish and tomcat java servers.
When I upgraded and made the necessary modifications to my app I could not get it to work on glassfish but had no problems on tomcat.
This error happens in the beginning of start up when I call the XmlManager constructor. I am clueless as to what it is because I can not recreate it on anything else but glassfish v2. I even created a new project and played around with some options.
Here is part of the stack trace:
DB errno:0
The log message is null.
com.sleepycat.dbxml.XmlException: Uncaught exception from C++ API, errcode = INTERNAL_ERROR
at com.sleepycat.dbxml.dbxml_javaJNI.new_XmlManager(Native Method)
at com.sleepycat.dbxml.XmlManager.<init>(XmlManager.java:56)
For now I am going to just use tomcat, but I would really like to know what is going on for both peace of mind and because I like some of the features of glassfish.
Not sure if this matters but I am deploying the web app through netbeans 6 for both glassfish and tomcat.
Thanks in advance for any help.

I don't think it is a library path problem. The java.library.path shows the right values. I did have it working fine on the previous version of berkeley xml. I did have a version mismatch problem but I deleted the other database. I did have problems uninstalling the old database and I had to do it manually (the uninstall was hanging). Maybe I didn't clean it up correctly. My confusion is if I didn't clean it up correctly why does it work on everything else but glassfish.
Thanks for your help.

Loading large XMLs to Berkeley XML DB

Hi all ,
I am trying to load a very big XML file to Berkeley XML DB from unix shell. I have created a container of type node storage with node index. It is taking around 15 minutes to load the document. My system configuration is 64GB RAM and 2 CPU each with 4 cores.It is very much require for me to use node storage with indexing for best xquery performanceIs there a way to improvise the loading performance ?

Hi,
DB XML is an embeddable database that means that it is supposed to be integrated into your application that in turn takes care about communication with client. That means if you want the server-client architecture you wouldn't have to take care of it yourself. For example, writing a Java servlet that under the hood connects locally to DB XML and does necessary stuff. If I remember correctly, there was one example (in the DB XML examples) that implements a servlet, but I have never look into it.
Vyacheslav

Java and Berkeley XML DB

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