Web Changing the face of the world : Ramesh

Ramesh, a senior technologist/scientist from Adobe, talked about how and what has web 2.0 done to change the world, especially the way the information is treated/used/processed etc...

Here are some of his points -

Real Time Web

• kind of content that is coming around
• no more old docs
• social networking
• live collaboration

experiencing the web - how the web is experienced, the way its accessed, used etc.

• Some tools are coming up in the VR world, which allows
  
• augmented reality -> web apps capturing reality and using the inputs
  

proliferating devices

• Already more web access from non PC devices
• More devices are coming through which access web differently

democratization of data

• Some govts have already started putting their data in public domain.
• Lots of application development opportunities based on that data.
• Cloud computing also coming around to provide processing power and applications for the data.

Buzzwords

• ActionScript
• ECMAScript
• Flex

Quite interesting talk :) Learned person, Ramesh.

Marty Hall : Why Ajax : Using Ajax in ur web apps

Why WebApps - Ajax

• Asynchronous JavaScript and XML => doesnt hold good anymore
  
• allow the browser to utilize the time when the main page is gone tofetch the result of your initial app
• Add/modify content on the webpage at runtime
  
• trends -> more jobs on Ajax than any other technology - php, vb, asp etc...

Ajaxifying an Application

• libraries - jQuery, ext-ja, dojo, yui, prototype, google closure, mootols
• Browser allow calls to only the server from where the original code came in, due to firewall issues.

• Situation 2 - Hybrid
  
• Libraries to use for new apps - JSF 2.0, Struts 2.0, Spring MVC 3.
• JSF is better because
• integrated in main code - jquery needs u to write javascript
  
• no javascript to write - a simple tag

• Situation 3 - Hardcore Ajax
• Google web toolkit
• Use java everywhere
• Write java code at front end -> compiles to javascript at run time
  
• Write java code at back end-> provides facility of communication in terms of java objects

Buzzwords

• Jboss Seam <-> JSF 2.0
  
• 
  

@GIDS 2010 Bangalore

I am going to be there at the "Great Indian Developer Summit" in Bangalore April 20th to 23rd 2010.

Its hosted at the lush green IISc campus, in the J N Tata Auditorium. Various pieces of info are available from the organizer website -

www.saltmarch.com

http://www.developermarch.com/developersummit/


It looks like an amazing place to be, full of tech discussions, and hopefully knowledge too...

Apple and India...

Well, this is sad, particularly for someone in India, who avoids getting cracked iPhones...

Only yesterday Apple and Airtel announced availability of iPhone 3GS in India and today I get to read this, that Apple is releasing a new/better hardware for iPhone coming summer.

So, basically, India as an iPhone market is going to lag behind the rest of world by at least one model this time around as well.

Sometimes, I dont understand Apple's marketing strategy, specially in Indian context. As an Economy, India is probably the largest in the emerging market economies closely behind China. That statement should alone prove to be a "lucrative market" for any company which aims for growth.

This is specially interesting when we look at the number of iPhones already used in India with cracked OS's.

This doenst help a company's revenues if the product is consumed in a market where the company doesn't officially sell the product.

Also, the number of iPhones used in India, should give Apple an indication about the marketability of their product in this market. Personally, I think as a product from Apple's stable, iPhone has a lot of glamour linked to it.
And therefore, huge possibilities in India for Apple.

The new iPhone's rumoured specs look stunning, 5 MP camera, better display resolution, more processing power, possible multi tasking, video calling camera and few other things. After reading that, my plans to order an iPhone 3GS have taken a back seat. I want to see this product coming to market, further to see, when does it come to India.

Apple seems to listening to customers.. the kind of improvements rumoured is possibly the exact list of things someone might say are downsides of iPhone...

Good luck Apple, and India, hoping for a better collaboration this time around...

in reference to: More on next-gen iPhone and Verizon iPhone dreams (view on Google Sidewiki)

Explain plan of Infobright

We all knw that Infobright is based on MySql. However, when I started with Infobright, I was equally unaware of both.

Today I got to know about Infobright's explain plan collection technique, and realized how different it is from Oracle's.

A typical explain plan from oracle talks about the path it follows to retrieve the data, and somehow makes common sense to read a plan.

On the other hand, an explain plan from Infobright looks nothing like the Oracle's plan. Its a set of cryptic rows put together. An example of such a plan -

2010-03-18 01:31:01 [4] T:-1 = TABLE_ALIAS(T:0,"myTableName")
T:-2 = TMP_TABLE(T:-1)
VC:-2.0 = CREATE_VC(T:-2,PHYS_COL(T:-1,A:20))
A:-1 = T:-2.ADD_COLUMN(VC:-2.0,AVG,"avg(col1)","ALL")
A:-2 = T:-2.ADD_COLUMN(VC:-2.0,MAX,"max(col1)","ALL")
A:-3 = T:-2.ADD_COLUMN(VC:-2.0,MIN,"min(col1)","ALL")
A:-4 = T:-2.ADD_COLUMN(,COUNT,"count(1)","ALL")
VC:-2.1 = CREATE_VC(T:-2,PHYS_COL(T:-1,A:2))
A:-5 = T:-2.ADD_COLUMN(VC:-2.1,GROUP_BY,"col2","ALL")
VC:-2.2 = CREATE_VC(T:-2,PHYS_COL(T:-1,A:5))
A:-6 = T:-2.ADD_COLUMN(VC:-2.2,GROUP_BY,"col3","ALL")
VC:-2.3 = CREATE_VC(T:-2,PHYS_COL(T:-1,A:7))
A:-7 = T:-2.ADD_COLUMN(VC:-2.3,GROUP_BY,"col4","ALL")
VC:-2.4 = CREATE_VC(T:-2,PHYS_COL(T:-1,A:11))
A:-8 = T:-2.ADD_COLUMN(VC:-2.4,GROUP_BY,"col5","ALL")
VC:-2.5 = CREATE_VC(T:-2,PHYS_COL(T:-1,A:12))
A:-9 = T:-2.ADD_COLUMN(VC:-2.5,GROUP_BY,"col6","ALL")
VC:-2.6 = CREATE_VC(T:-2,PHYS_COL(T:-1,A:13))
A:-10 = T:-2.ADD_COLUMN(VC:-2.6,GROUP_BY,"col7","ALL")
VC:-2.7 = CREATE_VC(T:-2,PHYS_COL(T:-2,A:-1))
T:-2.ADD_ORDER(VC:-2.7,DESC)
RESULT(T:-2)

And, guess what, to generate a plan, you have to change a setting in the initialization parameters file, and then bounce the db. I wonder if there have been any instances when someone had to look into production database's performance and therefore needed to look at some plan.

Being as new a system as it is, I cant really complain, since such things of maturity will slowly creep in. The focus right now is probably elsewhere, building the functionality, and probably performance.

in reference to: Infobright.org Forums | Enable MySQL Logging (view on Google Sidewiki)

Discovered BOINC 5 years ago, joined today :)

It was George, a colleague at Axa Tech in Switzerland who first introduced me to this idea. I was thrilled alright, but didnt join right away.

Today I did.

Its a nice feeling, and a feeling of giving back something to science.

http://en.wikipedia.org/wiki/Berkeley_Open_Infrastructure_for_Network_Computing

http://boinc.berkeley.edu/

I would not go into details how it works and all that. However, I would have to say, for whatever time your laptop/workstation remains idle, you can donate the processing power to a better cause. Absolutely fantastic idea, genuinely noble.

And then, look a the stats, people like me are contributing to the processing power generated to the extent of 4 pFLOPS, as against the fastest supercomputer system at mere 1.79 pFLOPS.

As I said, feels great. :)

I hope to inspire others to join in...

in reference to: BOINC (view on Google Sidewiki)

Connecting to an Oracle Server...which way is faster...

I've never came across this question as such, because its sort of given that you connect to a server any-which way the administrators define the policy. The tuning perspectives came in only afterwards.

However, in a recent situation, I had to connect to a remote server from my client system and was wondering whether I should connect using tnsnames.ora or should I use the basic authentication mechanism, using the complete connect string.

I thought that the tnsnames.ora would incur some latency in connections. On the other hand, connecting directly without using any such files is like doing a telnet to the server on a given port.

Also, I have seen that if you attempt to connect using the complete connect string from the tnsnames.ora file, it also works.

Since I was not clear myself, I did post this question on oracle forums. And a gentleman, Billy Verreynne took out some time to help explain the concept. Many thanks to him.

As it stands, the basic methodology of connection is same in both cases. However, if you happen to have a huge tnsnames.ora file, it would be an overhead to parse the file and get the connect string for the service name you attempted to connect to. But it would only make a difference, if your client connection process go into hundreds then it might make any noticeable degradation. Basically, client would have to parse the huge tnsnames file few hundred times per second.. then it might make a difference.

Billy also suggested that if you switch the server mode from dedicated to shared, it would help.

So, for my conclusions, its the same if you connect through tnsnames or through a native connect string.

availability of native drivers !!!

As I mentioned earlier, I was busy experimenting with a columnar database, InfoBright.

The experience till now is mixed, in some scenarios, the data loading is very good, as much as 40k rows per second, whereas through other channels its a poorer 500 rows per second. When I go with their built in loader, its lightening fast, but when I try from Pentaho or Informatica, its measly.

Apparantly, the drivers and the compatibility of the third party tools do play a role in attaining the performance.

The fact that they dont have any native driver published, is a huge bottleneck. Informatica dont even have a native connector for MySql, the more known cousin of InfoBright (being open source, the core engine of InfoBright is based on MySql only).

One thing came out of this experience for sure, the liking for open source got better and better. During the hunt to see the reason for slow performance from Pentaho, I even tried and managed to get the source code of the plugin (transformation) that pentaho uses for Infobright. Its pure java and it was a very powerful and awakening feeling to see the code of the item. I felt as if I have the power, the choice to make a difference, make it better. :)


I am currently exploring other options, one of them includes creating a dump file (read : csv) of the data, and then launching the command line tool to load the data into target db. I dont like it, but lets see if there is any better (read:faster) way around...

Its been a while...

Its been quite some time since I wrote anything to this blog, let alone anything valuable.

However, last few months have been quite eventful in my personal and professional life. I have landed a job with a company in Bangalore now, which works a lot more with open source systems/applications than my previous employer. I can easily say that this was one of the points in my decision making.

Currently, I am opening up to working on Ubuntu and probably virtualization, mysql, postgresql and most importantly, Informatica Powercenter and Pentaho. The suite of tools is just too exciting for me to find right words to express my feelings.

Recently I have picked up a project to do a Proof of Concept for using an open source columnar database and compare its behavior with oracle for a given application. Of course it involves data loading, and analytical queries, so there would be some interesting stats collection and comparison. Attempts to break a system are always more interesting than to make it J

Lets see how it goes…

Also, I would try to be more regular on the blog now onwards…

Compile all packages in a schema

BEGIN
FOR cur IN
(
SELECT OBJECT_NAME,
OBJECT_TYPE ,
owner
FROM all_objects
WHERE object_type IN('PACKAGE', 'PACKAGE BODY')
AND owner = ':OWNER
AND status = 'INVALID'
)
LOOP
BEGIN
IF cur.OBJECT_TYPE = 'PACKAGE BODY' THEN
EXECUTE IMMEDIATE 'alter package "' || cur.owner || '"."' || cur.OBJECT_NAME ||
'" compile body';
ELSE
EXECUTE IMMEDIATE 'alter ' || cur.OBJECT_TYPE || ' "' || cur.owner || '"."' ||
cur.OBJECT_NAME || '" compile';
END IF;
EXCEPTION
WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE('Errors compiling - ' || cur.owner ||'.'||cur.object_name);
END;
END LOOP;
END;

MDX Tutorial

MDX Tutorial

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Interesting Demos from Informatica

Pretty Basic Demo by Infa guys on their DW offering...
Informatica Enterprise Data Warehousing Demo

Another interesting one on Data Migration...
Informatica Data Migration

Top 12 Ruby on Rails Tutorials

Looks like an interesting set of tutorials...

Top 12 Ruby on Rails Tutorials

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tweaks around Oracle 11g on Hardy 64bit

I did an oracle 11g 64bit install on my 64bit core 2 quad using the resources available on internet and some past experience.

The tutorial here is great :

http://www.pythian.com/blogs/968/installing-oracle-11g-on-ubuntu-804-lts-hardy-heron

However, some things still show up after the initial setup is done. Here are bits of my experience -

1. Starting Enterprise manager after a reboot -
Try emctl status agent
The last line of the output should tell you whats happening. If its not running, start it using the following -
emctl start dbconsole
This thanks to http://www.linuxquestions.org/questions/linux-general-1/linux-5-oracle-11g-enterprise-manager-question-616532/

2. The ORACLE_SID variable must be declared in either /etc/profile (for a single database on the system) or on user's local profile.

Earning money using cloud Computing ??

I dont know much more about cloud computing, but it sure sounds like an interesting idea. The way it allows computing resources to be shared and connected through internet and all that. The benefit to the average developer is huge, getting computing power so cheap..

However, I think the reverse should also be true and could turn out to be pretty interesting. The way we (developers) use resources from the cloud for our computing purposes, we could also share our spare resources to the same cloud so that someone else might use them and allow us to earn some money in exchange. There would be some preconditions and requirements and what not, but essentially that should be a possibility...

I dont know for sure whether this concept already exists, but i would sure like to see that happening...

Blank Subject Reminder in Outlook...

1. Open your outlook.

2. Press Alt+F11. This opens the Visual Basic editor and then Press Ctrl+R which in turn open Project-Project 1 (left side).

3. On the Left Pane, one can see "Microsoft Outlook Objects" or "Project1", expand this. Now one can see the "ThisOutLookSession".

4. Double click on "ThisOutLookSession". It will open up a code pane.

5. Copy and Paste the attached code in the right pane. (Code Pane) and save it.

Private Sub Application_ItemSend(ByVal Item As Object, Cancel As Boolean)

Dim strSubject As String
strSubject = Item.Subject
If Len(Trim(strSubject)) = 0 Then
Prompt$ = "Subject is Empty. Are you sure you want to send the Mail?"
If MsgBox(Prompt$, vbYesNo + vbQuestion + vbMsgBoxSetForeground, "Check for Subject") = vbNo Then
Cancel = True
End If
End If
End Sub

For this you need to create a digital certificate. Go to http://office.microsoft.com/en-us/help/HP052495581033.aspx to see how to do it. Name your certificate whatever you like e.g No_Subject.

Once that’s done go back to the code window, click Tools, Digital Signature, Choose - and choose that signature you just created. Hit ok, save this project, close it. Close Outlook completely too.

Start up Outlook, you get the security box; click always trust running this macro thing. And you’re done! Try sending a message without body, you’ll get an alert. Now even if you restart outlook it’ll still work.

Courtesy a colleague, Mukesh.

All about Dual Table : AskTom

A very very interesting article from AskTom on dual table, its purpose and usage and everything else about it...

Here's some excerpts from it, leaving the rest for reading...

"DUAL is owned by SYS.  SYS owns the data dictionary, 
therefore DUAL is part of the data dictionary.  You are not to modify the data dictionary 
via SQL ever -- wierd things can and will happen"

More

the optimizer understands dual is a magic, special 1 row table.  It stopped on the 
select * because there is to be one row in there.  Its just the way it works.

Read the rest of article here...

Ask Tom "All about the DUAL table "

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Oracle SQL tuning - Burleson Consulting

Burleson Consulting website has come to rescue in many situations. For many questions their site provides great pointers and ideas.

Here's a series of papers/articles on Oracle SQL Tuning -

Oracle SQL tuning parameters

And, here's an article on tuning of individual SQL Statements -

Tuning Individual SQL Statements

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Beware of Question Authorities « H.Tonguç Yılmaz - Oracle Blog

Beware of Question Authorities

Following suggestions are from Mr.Lewis Blog ;

1. If it’s not dated - don’t assume it’s true*
   
2. If its date is more than about 18 months old - don’t assume it’s (still) true*
   
3. If there’s no version number - don’t assume it’s true*
   
4. If it’s not your exact version number - don’t assume it’s (still) true
5. For ‘technical implementation’ details, if there’s no platform mentioned - don’t assume it’s true
6. For ‘technical implementation’ details, if the platform’s not the same as yours - don’t assume it’s true
7. If there’s no rational justification supplied, and no repeatable test case - don’t assume it’s true.

And even when all the details are perfect and there is a repeatable test case - and even after the repeatable test case produces the same results - ask yourself this question

• Could there be a different explanation for the same set of results - and if so, how badly could this advice damage my system, and how hard would it be to test my alternative hypothesis ?

Once you’ve got through that lot - then you might be safe trying the advice on a development system.

Mr.Kyte also mentions this problem under the ‘Question Authority.’ terminology;

There are lots of ‘experts’ out there;

• Make them prove everything
• Statements that should raise your eyebrows:

•     It is my opinion…
•     I claim…
•     I think…
•     I feel…

• Everything can (and should) be proven - TKPROF goes a long way hereStatspack is great‘Runstats’ is a tool I use as well (search asktom for runstats)

• Things change, expect that

Remember a test becomes a proof when;

• it has a specification- the results are reproducible
• alternative explanations have been eliminated
• it is published- it survives peer-group review

Reference
“The Burden of Proof” presentation by Jonathan LewisDon’t take any “guru’s” word, test it and make sure you are convinced of the results..

Beware of Question Authorities « H.Tonguç Yılmaz - Oracle Blog

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SQL - Difference Between Hash Join & Merge Join

Difference Between Hash Join & Merge Join

Merge Join :Oracle performs a join between two sets of row data using the mergejoin algorithm. The inputs are two separate sets of row data. Output isthe results of the join. Oracle reads rows from both inputs in analternating fashion and merges together matching rows in order togenerate output. The two inputs are sorted on join column.

Hash Join :Oracle performs a join between two sets of row data using hash joinalgorithm. Input and Output same as Merge Join. Oracle reads all rowsfrom the second input and builds a hash structure (like has table injava), before reading each row from the first input one at a time. Foreach row from the first input, the hash structure is probed and matchingrows generate output.

SQL - Difference Between Hash Join & Merge Join

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