Smalltalk with James Robertson

You might have noticed that I used the VisualWorks workspace in a few recent ObjectStudio screencasts; now Andreas has addressed the issue that drove me to that:

What are Workspace Variables? Well, a Workspace Variables is just like any other variable, except that it is defined in the context of the current Workspace. This way you can get always the content of the variable, if you use the same Workspace.

That's what's cool about Smalltalk - want a feature? You can add it, whether you're an expert like Andreas or not.

Technorati Tags: objectstudio, workspace

Spotted in self halt

For example, to access the Google Spreadsheets APIs and Tools, you need to download the Java client libraries and all its dependencies. The paths to there Jars must be known to the JVM and can be set through JNIPort. For easy deployment, I put together a single jar using an Ant build script

That's pretty cool - there are tons of Java libraries that connect to tons of things and JNIPort opens up that world to Smalltalk. It's all about reuse :)

Technorati Tags: java, JNIPort

Michael has pushed out some new info on Xtreams - check it out.

Technorati Tags: xtreams, streams

Interesting video site for Smalltalk tutorials - the Smalltalk Medicine Show, run by Chris Cunnington. Chris does a new video every week - the Medicine Show has some interesting video up on HttpView2.

Technorati Tags: video, tutorials

Geert Claes has set up a new "World of Smalltalk" site - I'll be setting up a podcast calendar so he can include that.

Spotted in Planet Squeak

Alexandre Bergel organizes a new Pharo sprint in Argentina (Buenos Aires or Rosario).

Technorati Tags: pharo, argentina

Today's Smalltalk Daily looks at using Statement Caching against Oracle (version 9 and up) with VisualWorks. If you're looking for a particular topic, you can find it with the Media Search application on our site.

The code used is below; To watch, click on the viewer:

"The following are two examples, one uses statement caching, the other does not."

conn := OracleConnection new. 

"Verify whether the loaded OCI supports Statement Caching."
conn supportStatementCaching.

"Set to use statement caching."
conn useStatementCaching: true.

conn environment: 'ORACLEDB'; 
        username: 'username'; 
        connect: 'password'. 

"Get Statement Cache Size, the default is 20."
conn getStatementCacheSize.

"Set Statement Cache to desired size."
conn setStatementCacheSize: 30.

"Verify the new Statement Cache Size."
conn getStatementCacheSize.


t1 := Time millisecondsToRun:[

       " | conn sess ansStrm |"

     100 timesRepeat: [
		sess prepare:  'select * from sys.all_tables where TABLE_NAME=''DUAL'''.
		sess execute.
		ansStrm := sess answer.
		res := ansStrm upToEnd.
	].
].
Transcript 
	cr; 
	show: 'Time spent when using Statement Caching: ', t1 asFloat printString.

conn := OracleConnection new. 

"Set to use statement caching."
conn useStatementCaching: false.
conn environment: 'ORACLEDB'; 
        username: 'username'; 
        connect: 'password'. 

t2 := Time millisecondsToRun:[
       " | conn sess ansStrm |"
     100 timesRepeat: [
		sess prepare:  'select * from sys.all_tables where TABLE_NAME=''DUAL'''.
		sess execute.
		ansStrm := sess answer.
		res := ansStrm upToEnd.
	].

].

Transcript 
	cr; 
	show: 'Time spent without using Statement Caching: ', t2 asFloat printString.

You can download the video directly here. If you like this kind of video, why not subscribe to "Smalltalk Daily"?

Technorati Tags: oracle, database, statement, caching, visualworks

Andreas is one of the most active guys doing Squeak development - now he's got a new forum for telling us what he's up to

Technorati Tags: squeak

Today's Smalltalk Daily looks at using Oracle's pre-fetch capability with VisualWorks. If you're looking for a particular topic, you can find it with the Media Search application on our site.

The code used is below; To watch, click on the viewer:

"Connect to an Oracle database."
conn := OracleConnection new.
conn username: 'username';
password: 'password';
environment: 'ORACLEDB'.
conn connect.

sess := conn getSession.

"Drop the test table if existed."
sess prepare: 'DROP TABLE TESTTABLE';
	execute;
	answer;
	answer.

"Create a test table."
sess prepare:  'CREATE TABLE TESTTABLE(
	NUMMER int ,
	BEMERKUNG varchar2 (30)
	)';
	execute;
	answer;
	answer.

"Set the number of recrods being inserted."
loopCount := 1000.

"The SQL used to do insert."
sql := 'INSERT INTO TESTTABLE VALUES (?, ?)'.

"Insert: Using array binding."
insertTime2 := Time millisecondsToRun: [
|bindArray numArray stringArray |
    numArray := Array new: loopCount.
    stringArray := Array new: loopCount.
	1 to: loopCount do: [ :i|
		numArray at: i put: i.
		stringArray at: i put: 'test'.
	].			
	bindArray := Array with: numArray with: stringArray.
	sess prepare: sql.
         sess bindInput: bindArray;
		execute;
		answer;
		answer.
].

"Print out the miliseconds spent."
Transcript 
	cr; 
	show: 'Time spent using array binding: ', insertTime2 asFloat printString.

"Set times to repeat."
loopCount := 1.

"Set the SQL to do the fetch."
sql := 'SELECT * from TESTTABLE'.

"Default value of prefetch rows is 1."
sess setPrefetchRows: 1.

selectTime1 := Time millisecondsToRun: [
	1 to: loopCount do: [ :i|
		sess prepare: sql;
		execute.
		ans := sess answer.
		res := ans upToEnd.
    	].
].

"Print out the miliseconds spent."
Transcript 
	cr; 
	show: 'Time spent when prefetch rows  is 1: ', selectTime1 asFloat printString.

"Set prefetch rows to 100."
sess setPrefetchRows: 100.

selectTime2 := Time millisecondsToRun: [
	1 to: loopCount do: [ :i|
		sess prepare: sql;
		execute.
		ans := sess answer.
		res := ans upToEnd.
    	].
].

"Print out the miliseconds spent."
Transcript 
	cr; 
	show: 'Time spent when prefetch rows  is 100: ', selectTime2 asFloat printString.

"Set prefetch rows to 500."
sess setPrefetchRows: 500.

selectTime3 := Time millisecondsToRun: [
	1 to: loopCount do: [ :i|
		sess prepare: sql;
		execute.
		ans := sess answer.
		res := ans upToEnd.
    	].
].

"Print out the miliseconds spent."
Transcript 
	cr; 
	show: 'Time spent when prefetch rows is 500: ', selectTime3 asFloat printString.

You can download the video directly here. If you like this kind of video, why not subscribe to "Smalltalk Daily"?

Technorati Tags: visualworks, database, oracle, prefetch

I just spotted another Smalltalk implementation:

ChocoSmallTalk is a hybrid SmallTalk/Lisp implementation in Common Lisp. The purpose of this project is an embedded SmallTalk in Lisp, known as a meta-circular implementation of lisp as an add-on. As time permits this project should be usable on ARM based processors on handhelds to make a real lisp-smalltalk machine.

Technorati Tags: lisp, embedded