Direct IO,Asynchronous IO and relationship with database performance

What is concept of Direct IO, Asynchronous IO from the DBA prospective? How does it relates to the database performance?
Any simple explanation will be highly appreciated. Thanks in advance.

918868 wrote:
What is concept of Direct IO, Asynchronous IO from the DBA prospective? How does it relates to the database performance?
Any simple explanation will be highly appreciated. Thanks in advance.yet another interview question from you?

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Homgeneous System Copy with Java and DB2 with database tools.

Hello,
we have an single java stack (netweaver 2004s) and tried a system copy with database tools.
Source System: DP2, dp2adm, db2dp2, sapdp2db
Target System: SP2, sp2adm, db2sp2, ???
We followed the documentation "System copy for SAP systems based on sap netweaver 2004s SR1 JAVA. We exported the SDM on the source system made a redirected restore with db tools and tried to install a new target system.
During the import in the target system using sapinst we get in the
phase run java migration tool kit the following error message.
Caused by:
com.sap.engine.frame.core.configuration.ConfigurationException: Error
while connecting to DB.
at
com.sap.engine.core.configuration.bootstrap.ConfigurationManagerBootstrapImpl.(ConfigurationManagerBootstrapImpl.java:49)
... 14 more
Caused by: com.ibm.db2.jcc.a.SqlException: Connection authorization
failure occurred. Reason: userid revoked.
What I didn't understand is, that in the documenation it is mentioned, that you have to use the same java database connect user. But during the installation of the target system (SP2) I cannot change the java database connect user to sapdp2db. I'm only allow to enter sapsp2db. That might then cause the connection problem.
Regards
Alexander Türk
I

Hi Alexander
yes , give it a try , but see note
970518 Hom./Het.System Copy SAP NetWeaver 2004s SR2
and all other related notes , if it matches your environment .
Best regards
dirk

New HP EVA6000 SAN and now bad database performance problems

Hello,
we changed our SAN Hardware to a HP EVA6000 and moved all Data to there.
It is intended that storagesystem is for all Servers (File/Print, Exchange, Oracle Databases and MSSQL Databases).
According to the best practice papers of HP we created one big discgroup (fata harddiscs) and created virtual discs for our servers.
After doing this the database performance was terrible bad!
Especially the multiple random IO is absolutely worse.
As a first countermeasure we created a second discgroup on faster harddiscs and moved the database contents to there. We analyzed the IO and moved several database file to different virtual discs.
The performance is better now, but still not like the 4 year old SAN System!
Of course we questioned HP and even let them do a performance analysis but up to now we have no solution... The performance analysis report will be available on thursday.
Does anybody had the same experience or how did you configure the Database and EVA SAN to work with an appropiate performance?

Hi,
I'm not an Oracle person, but do work with EVA SAN's.
Your 48 FATA disk, disk group is capable of 4800 I/O operations per second [48 x 100] but the disks are only rated for 30% duty cycle and spin at 7200 rpm.
The 16 FC drive Disk Group I/O operations rating depends on the speed the disks spin at. 10K rpm disks are rated at 130 I/O per sec [2080 for the group] and if they are 15K rpm disks then 170 I/O per sec [2720 for the group]. Both are rated for 100% duty cycle.
I seem to recall having have read somewhere that Oracle prefers to have it's logs on separate storage to it's data.
If your shelves had the spare disk slots I would put in 72 GB 15K rpm disks up to the capacity required {+ overhead } + head room for reasonably predictable growth over the anticpated life of the equipment.
Here is a link to the HP Best Practice guide for EVA 4/6/8000's
http://h71028.www7.hp.com/ERC/downloads/4AA0-2787ENW.pdf
I hope this helps you understand the storage that you are working with a bit better. The old saying of "more heads make for better performance" is still true, however budget can have some affect in performance. ;-)
Jim

Crmm_erm_cat and relationship between database questions and activities

Hello Guys,
Using this transaction, it´s possible to make the relationship between the questions from the solution database with activities, and it´s possible to locate some activities over there. These activities are not apearing. Is there something else in the transaction, or additional transaction, I have to execute, to make the crmm_erm_cat work fine?
cheers
Luiz David

Already solved, thanks

JSP and Images with database

Ok, I have looked around on posts on this forum but still haven't come across an answer. I am trying to create a simple jsp page that contains some thumbnail images. The image locations are stored in a mysql database (e.g. http://www.somewhere.com/images/image1.jpg"). Assuming that I didn't know how many images were stored in the mysql table, how can I set up a jsp page that will automatically retreive all the image locations from the database and put the appropriate tags in the jsp to display all the images in an html table? In other words, I am trying to avoid writing in the jsp page a bunch of <tr><td><img src=.....></td></tr> statements. Do I need to do this with a tag library? You help is much appreciated! Let me know if I need to be more clear.
Keith

<%@page import="java.sql.*" %>
<table boder="1">
<%
Statement statement;
Connection conn;
String url = "jdbc:mysql://localhost/dbName";
String user = "username";
String pass = "password";
try {
    class.forName("com.mysql.jdbc.Driver");
    conn = DriverManager.getConnection(url, user, pass);
    statement = conn.createStatement();
String query = "SELECT images FROM database";
ResultSet results = statement.executeQuery(query);
while(results.next()) {
%>
    <tr>
        <td><img src="<%= results.getString("images") %>"></td>
    </tr>
<% } %>
</table>The while loop will loop through your result set and print the table row for each image it finds in the query.
Hope this helps,
Jon

Saving movies directly onto time capsule and synching with apple tv

hi all
i've just got hold of a 1tb time capsule. i have a heap of home movies that i want to move from tape to computer, and reckon there is over 100gb of footage. i don't have enough hard drive space for all of them
i had hoped to be able to transfer them via my laptop directly to time capsule. is this possible? And can stuff be saved on time capsule that is not then stored on the hard drive?
to complicate things, i'm hoping to be able to view them on apple tv, and hoped to be able to synch the apple tv with the time capsule
Am i making things very complicated?
Many thanks for any help

mathewprior wrote:
hi all
i've just got hold of a 1tb time capsule. i have a heap of home movies that i want to move from tape to computer, and reckon there is over 100gb of footage. i don't have enough hard drive space for all of them
i had hoped to be able to transfer them via my laptop directly to time capsule. is this possible?
Yes.
And can stuff be saved on time capsule that is not then stored on the hard drive?
Yes.
to complicate things, i'm hoping to be able to view them on apple tv, and hoped to be able to synch the apple tv with the time capsule
I don't know about Apple TV. I don't think you can sync a Time Capsule, but check either in the Time Capsule forum, hidden in the +Digital Life+ section, at: http://discussions.apple.com/forum.jspa?forumID=1253 and/or the MobileMe forums, also in +Digital Life,+ at: http://discussions.apple.com/category.jspa?categoryID=116
One additional consideration is backups. Most backup apps (including Time Machine) won't back up a Time Capsule (Apple's main intention for the Time Capsule is as a destination for backups, not a source). There is a feature in +Airport Utility+ where you can attach an external drive to one and "archive" the TC's disk to the external. So be sure you have a good backup plan.

How 2 create a Jtext box and Jcombobox with database connectivity

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.sql.*;
public class StockReport1 extends Frame implements ActionListener
JLabel l1,l2,l3;
JTextField t1,t2,t3;
JPanel p1,p2;
JButton b2,b4,b5;
static Connection cn;
static Statement st;
static ResultSet rs;
public StockReport1()
l1=new JLabel("Name");
l2=new JLabel("Age");
l3=new JLabel("Native");
t1=new JTextField(20);
t2=new JTextField(20);
t3=new JTextField(20);
p1=new JPanel();
p2=new JPanel();
p1.add(l1);
p1.add(t1);
p1.add(l2);
p1.add(t2);
p1.add(l3);
p1.add(t3);
b2=new JButton("Exit");
b4=new JButton("Next");
b5=new JButton("Previous");
b2.addActionListener(this);
b4.addActionListener(this);
b5.addActionListener(this);
p2.add(b2);
p2.add(b4);
p2.add(b5);
p1.setLayout(new GridLayout(3,1));
p2.setLayout(new GridLayout(1,6));
add(p1);
add(p2);
setSize(500,500);
setVisible(true);
setLayout(new FlowLayout(FlowLayout.LEFT,30,40));
addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);}});
public void actionPerformed(ActionEvent ae)
try
if(ae.getSource()==b2)
System.exit(0);
if(ae.getSource()==b4)
if(rs.isLast()==false)
rs.next();
display();
else
rs.last();
display();
if(ae.getSource()==b5)
if(rs.isFirst()==false)
rs.previous();
display();
else
rs.first();
display();
catch(SQLException se)
se.printStackTrace();
public static void main(String arg[])
new StockReport1();
public void display()
try
String s1=rs.getString(1);
String s2=rs.getString(2);
String s3=rs.getString(3);
t1.setText(s1);
t2.setText(s2);
t3.setText(s3);
catch(SQLException se)
se.printStackTrace();
}

don't mix up with awt and swing, use JFrame instead of Frame.
in display method just set the value of the result set to the textfields.
or put all the data into arraylist after each next button click just read the value and put into textfields

Big problem (and doubts) with binding performance

In a JavaFX mobile application I'm developing, I have a sequence of objects and a simple form with a text field and a list of items. The list of items must be populated with the sequence; as the user types in the text field, the list gets filtered properly.
This worked perfectly with some mock data (a handful of items), but it's really a disaster after I've tried to throw in real data (1000 - 2000 elements). I don't know whether it's a bug of JavaFX, a bug of mine, or if binding must not be perused. Before posting the code, there's some guideline I should be aware of, such as the max. feasible size of a sequence?
BTW, I must say that I'm not even able to get a JSON file through a parser, instantiating objects and adding them to a sequence. It's painfully slow and basically I can't even see its going on after about 100 elements.

Now, the relevant part of the controller.
package it.tidalwave.bluebillmfx.taxon.controller;
import javafx.animation.Timeline;
import javafx.animation.KeyFrame;
import it.tidalwave.bluebillmfx.taxon.model.Taxonomy;
import it.tidalwave.bluebillmfx.taxon.model.Taxon;
public class TaxonomyBrowsingScreenController
    public var selectedTaxon: Taxon;
    public var taxonomy: Taxonomy;
    public var filter: String = "";
    var leading = "";
    function matches (taxon : Taxon, string: String) : Boolean
        def m = (string == "") or taxon.displayName.toLowerCase().startsWith(string.toLowerCase());
        println("matches({taxon}, *{string}*) => {m}");
        return m;
    public var filteredSpecies = bind taxonomy.species[species|matches(species, filter)] on replace
        println("trigger begins");
        leading = commonRoot(filteredSpecies);
//        println("Selected {userInput} -> {filteredSpecies}");
        if ((leading != "") and (filter != leading))
            println("ROOT: {leading}");
        if (sizeof filteredSpecies == 1)
            selectedTaxon = filteredSpecies[0];
            println("SINGLE SELECTION {selectedTaxon}");
        else
            selectedTaxon = null;
        println("trigger ends");
}Edited by: Fabrizio.Giudici on May 21, 2009 1:42 AM

Problem with database-Studio

Hello
We use MaxDB for our SAP Systems and for our own applications(none SAP)
We upgradet our none-SAP Database from 7.7 to 7.8.02.21.
Then we tried the new Database Studio.
With problems!?
We have a schema BWALLE and a user BWPROGI.
When connecting to the database with SQL-Studio as BWPROGI we can see the schema BWALLE and all our tables.
When connecting to the database with Database Studio as BWPROGI we can't see the schema BWALLE and we can't see our tables??!!
We see 2 users BWPROGI and DBABW(the administrator).
Under BWPROGI there are no schemas!??
Under DBABW there are schemas(dbabw,domain,sysinfo) and all the tables/views belonging to these schemas.
What do we miss???
Why can we access our tables/views/indexes with SQL-Studio and not with Database-Studio.
Any help welcomed
Regards
Albert
Edited by: Albert Beermann on Nov 23, 2011 10:45 AM
Some more informations:
We have a group BWALLE nouser BWALLE.
The owner of the Schema BWALLE is the group.
The user BWPROGI is member of the Group BWALLE.
When connecting with SQL Studio as BWPROGI we see the schema BWALLE and all tables in the schema.
When connecting with MAXDB Maestro as BWPROGI we see the schema BWALLE and all tables.
When connecting with Database Studio as BWPROGI we can't see the schema BWALLE and don't see any table.
Connecting with SQL-Studio as BWPROGI shows the tables in schema BWALLE and we can read,update,... the data,
but with MAXDB 7.8 we get an error when doubleclicking on a table to look at the table structure.
With MAXDB Maestro everything works as expected.
Regards
Albert

Hello
How to do this???
Alter user BWPROGI DBA??
BWPROGI is member of group BWALLE and for group members i can only set mode resource or standard!
Or do you mean something else?
Regards
Albert

Asynchronously writing and callback function

hi everybody,
i am working on an asynchronous write operation as described in
'Asynchronously Reading and Writing with the NI-DAQmx Visual C++ Class Library'
in the Visual Studio .NET documentation.
I've worked with asynchronous read functions and callbacks (the OnEvent function in this example) before, and it worked
well.
Atm i am doing output to 16 digital outputs on my PCI6259 card. I want to output a waveform stored in a vector containing about 1000 samples.
So i installed the event handler for my writer object, and started the output by calling
'WriteMultiSamplePortAsync'.
The problem is, that the callback function 'OnEvent' is called after the first sample of my vector is sent, and not after the complete vector.
i need to know when my whole buffer is through, because i have to recalculate it and send it again...
Anyone has an idea where the problem is?
Thx in advance
markus

Well i've attached a somehow simplified code of my problem.
First i start two tasks, one counter, which acts as sample clock for my digital output, and the digital output task itself.
In this example i use a output frequency of 100kHz.
Then an event handler for my digital write operation is installed.
Next, i create a vector with size 1000, fill it with some data and write it out calling 'WriteMultiSamplePortAsync'
What i would expect now, is that the OnEvent-function is called, as soon as all of the 1000 samples of my output vector have been sent.
But what really happens is that OnEvent is called after the first of the 1000 samples has been written.
As i said before, the same procedure works fine with analog input tasks.
Regards
Markus
Attachments:
AsyncDigitalOut.cpp ‏3 KB

Compare editable alv output with database fields

I generated 1 editable alv report with attaching flat file data,
but i want to change the wrong fields in alv output and compare with database filds for validation.
but when i do this . it takes previous entries of flat file.
how can i solve it?

Your title is much better than in the first post, however your problem description hasn't changed.
Let me guess, you are importing a flat file, present the contents in an editable ALV grid, some values are being changed, and now the changed values do not reflect in the internal table, instead you are seeing the values as imported from the file?
If yes -> FAQ, please search for the many previous discussions of this topic.
Thomas

Syncing Outlook Calendars and Contacts with iPhone - There is NO SOLUTION

I have searched the Apple support forums, Mac Forums, MS forums, spoken to Microsoft Support and iCloud support. Everybody says that there is no way to directly sync Outlook Calendars and Contacts with iPhone and other remote devices and nobody has a work around. I see 100s of forum threads started with this issue, most have no answer and the few that do are not offering solutions. I post this as a final effort to seek a solution! Who will be my savior? Or should I just admit defeat and allow myself to be cast aside in the battle between two giant corporate babies who don't like to play in the same sandbox?
Is my knight in shining armor out there?!

The information is correct, MS do not support the Dav standard in Outlook for Mac (but they do in Outlook for Windows), until they add support for it Calendars and Contacts will not work with Outlook for Mac.

Oracle database Performance testing

What are the procedure to dp Oracle performance Testing???
Is there any tools to do Oracle database Performance or load testing??

insa wrote:
OS- windows
DB-Oracle11gr2
Just i want check if 100 of users using my Application at a time what will be the performance of my database??Database performance is dependent on a number of factors - where application design, application code and data model, are critical components.
And these components need to be designed, written, and implemented with performance and scalability as primary requirements. From design issues like using 3NF correctly, to coding issues like using bind variables correctly.
You cannot simply slap design and code together, run that against the database, and then tune database performance. That is not the correct approach. Oracle database technology performs very well. It is the application that does not perform. It is the design that does not perform. It is the architecture that does not perform.
When I see the comment that someone wants to test database performance, I see someone not understanding what determines performance - and incorrectly thinking that the database is a black box, and that this black box's performance can be tuned and set, irrespective of the data model, application code and architecture used.

TA25361 I have a ton of documents and databases in AppleWorks v 6.0 that I can no longer open on my MacBook Pro. Is there any way to recover this info? Some documents can be opened and resaved with textedit, but not my database with all important addres

I have a ton of documents and databases in AppleWorks v 6.0 that I can no longer open on my MacBook Pro. Is there any way to recover this info? Some documents can be opened and resaved with textedit, but not my database with all important addresses.

I tried Peggy's List > Select All > Copy > Paste into an AW spreadsheet suggestion.
In my case, pasting into the spreadsheet lost all text formatting (mostly text set to bold). The results of formulas were pasted, and checkboxes were pasted as "on" or "off". The DB did not contain any pop-up menus or radio buttons, but I expect they would transfer as a number showing the list position of the chosen item.
Pasting the copied List view data into a Numbers table gave a result similar to that with AppleWorks. I selected B2 as the target cell (for top left cell of the pasted data) to avoid any effects of posting into a header row or column. Bold and regular text formatting looked the same as it had in AW's List view.
Based on that, I'd slip the 'paste into an AppleWorks Spreadsheet step, and paste directly into a Numbers Table.
Regards,
Barry

Upgrade ERP database 11g and ATG7 with SSO integation

Please let us know how to Perform Upgrade ERP database 11g and ATG7 with SSO integation .
Regards .

We have completed to upgrade ERP database from 9.2.0.6 to 11.2.0.1 and also apply ATG 7 on Test instance.
And user finish testing , there is no issue after upgrade and application can work as normal.
On Test instance we didn't implement Single Sign On
But on Production we have Single Sign ON.
Now we plan to upgrade on Production instance. But we afraid that we will found any issue on Production relate to SSO. Becase we don't have a chance to test it.
My question is:
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Direct IO,Asynchronous IO and relationship with database performance

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