MacLochlainns Weblog

Michael McLaughlin's Technical Blog

Site Admin

Archive for the ‘Java’ Category

Hiding a Java Source

without comments

The ability to deploy Java inside the Oracle database led somebody to conclude that the source isn’t visible in the data catalog. Then, that person found that they were wrong because the Java source is visible when you use a DDL command to CREATE, REPLACE, and COMPILE the Java source. This post discloses how to find the Java source and how to prevent it from being stored in the data catalog.

You can verify that the Java class and source files exist with the following query:

1
2
3
4
5
6
7
8
COLUMN object_name FORMAT A20 HEADING "Object Name"
COLUMN object_type FORMAT A12 HEADING "Object Type"
COLUMN STATUS      FORMAT A14 HEADING "Object Status"
SELECT   object_name
,        object_type
,        STATUS
FROM     user_objects
WHERE    object_name = 'ReadFile';

It displays:

Object Name          Object Type  Object Status
-------------------- ------------ --------------
ReadFile             JAVA SOURCE  VALID
ReadFile             JAVA CLASS   VALID
 
2 rows selected.

Then, you can use the following query to discovery a Java library created by a SQL command:

1
2
3
4
5
6
COLUMN line FORMAT 9999 HEADING "Line|#"
COLUMN text FORMAT A66  HEADING "Text"
SELECT   line
,        text
FROM     user_source
WHERE    name = 'ReadFile';

It displays the following:

 Line # Text
------- ------------------------------------------------------------------
    1   // Java library imports.
    2   import java.io.File;
    3   import java.io.BufferedReader;
    4   import java.io.FileNotFoundException;
    5   import java.io.IOException;
    6   import java.io.FileReader;
    7   import java.security.AccessControlException;
    8
    9   // Class definition.
   10   public class ReadFile {
   11     // Define class variables.
   12     private static File file;
   13     private static FileReader inTextFile;
   14     private static BufferedReader inTextReader;
   15     private static StringBuffer output = new StringBuffer();
   16     private static String outLine, outText;
   17
   18     // Define readText() method.
   19     public static String readText(String fromFile)
   20       throws AccessControlException, IOException {
   21       // Read file.
   22       try {
   23         // Initialize File.
   24         file = new File(fromFile);
   25
   26         // Check for valid file.
   27         if (file.exists()) {
   28
   29           // Assign file to a stream.
   30           inTextFile = new FileReader(file);
   31           inTextReader = new BufferedReader(inTextFile);
   32
   33           // Read character-by-character.
   34           while ((outLine = inTextReader.readLine()) != null) {
   35             output.append(outLine + "\n"); }
   36
   37           // Assing the StringBuffer to a String.
   38           outText = Integer.toString(output.toString().length());
   39
   40           // Close File.
   41           inTextFile.close(); }
   42         else {
   43           outText = new String("Empty"); }}
   44       catch (IOException e) {
   45         outText = new String("");
   46         return outText; }
   47     return outText; }}
 
47 rows selected.

You can eliminate the source by compiling the Java library outside the database. Then, you use the loadjava utility to load the only the class file into the data catalog. The syntax would be the following command for an importer user in a video Pluggable Database (PDB):

loadjava -r -f -o -user importer/importer@video ReadFile.class

You should know that this syntax is disallowed by the loadjava utility, notwithstanding it’s found in the Oracle Database 12c documentation:

loadjava -r -f -o -user importer@video/importer ReadFile.class

You can verify that only the Java class file exists with the following query:

1
2
3
4
5
6
7
8
COLUMN object_name FORMAT A20 HEADING "Object Name"
COLUMN object_type FORMAT A12 HEADING "Object Type"
COLUMN STATUS      FORMAT A14 HEADING "Object Status"
SELECT   object_name
,        object_type
,        STATUS
FROM     user_objects
WHERE    object_name = 'ReadFile';

It displays:

Object Name          Object Type  Object Status
-------------------- ------------ --------------
ReadFile             JAVA CLASS   VALID
 
1 row selected.

Hope this helps those who want to hide the Java source files.

Written by maclochlainn

July 22nd, 2014 at 10:23 pm

Java File IO & NIO2

without comments

Java 6, or the java.io.* package which has been around a long time has known limits. There are some noted issues with the Java 6 java.io.* package, and why I wrote the FileIO.java file back in 2002. The FileIO.java class creates a series of static methods that let you read, write, copy, and move files both locally and across the network.

  • Many methods fail to throw exceptions
  • A number of simple methods are missing, like the copy and move methods
  • There isn’t any support for symbolic links
  • Many methods fail to scale with large files

The Java 7 introduces the java.nio.file.* package, and it does the following:

  • Works more consistently across platforms
  • Provides improved access to more file attributes
  • Provides improved exception handling
  • Supports non-native file systems

A student asked me to post the FileIO.java file. So, I posted it on the github.com site. I hope it helps simplifies the use of File IO operations. Admittedly, it’s easier to read and write a file with Java 7. The following provides a complete example class:

import java.awt.Dimension;
import java.awt.Font;
import java.io.*;
import java.nio.file.*;
import java.nio.charset.Charset;
import javax.swing.JOptionPane;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
 
public class ReadWriteFile {
 
    // Constructor for objects of class ReadFile
    public ReadWriteFile() {}
 
  // Write a file.
  public static void writeFile(String fileName, String fileText) {
    // Declare a file path.
    Path p = Paths.get(fileName);
 
    // Write a file.
    try {
      BufferedWriter bw =
        Files.newBufferedWriter( p, Charset.forName("ISO-8859-1")
                                  , StandardOpenOption.CREATE, StandardOpenOption.APPEND );
      bw.write(fileText, 0, fileText.length());
      bw.close(); }
    catch(IOException ioe) {
      System.out.println("Error writing a file."); 
      System.exit(0); }}
 
  // Read a file.
  public static String readFile(String fileName) {
    // Declare a String to hold the file.
    String text = "", line = "";
 
    // Declare a file path.
    Path p = Paths.get(fileName);
 
    // Write a file.
    try {
      // Read the file.
      BufferedReader fileInput =
        Files.newBufferedReader(p,Charset.forName("ISO-8859-1"));
 
      // Read and process first line.
      line = fileInput.readLine();
      text = line + "\n";
 
      // Read and process second thru last lines.
      while (line != null) {
        line = fileInput.readLine();
        if (line != null)
          text += line + "\n"; }
 
      // Close the file input.
      fileInput.close(); }
    catch(EOFException eofe) {
        System.out.println("No more lines to read.");
        System.exit(0); }
    catch(IOException ioe) {
        System.out.println("Error reading file."); 
        System.exit(0); }
 
    // Return a String value.
    return text;
  }
 
  // Declare a static main to read a text file.
  public static void main(String[] args) {
    // Declare local object types.
    JOptionPane op = new JOptionPane();
    JScrollPane sp;
    JTextArea ta;
    Object[] options = {};
 
    // Instantiate a test class.
    ReadWriteFile rwf = new ReadWriteFile();
 
    // Text the readFile method.
    if (args.length > 0) {
      // Set the value and formatting of the text area.
      ta = new JTextArea(rwf.readFile(args[0]));
      ta.setFont(new Font(Font.SANS_SERIF,Font.PLAIN,14));
      ta.setLineWrap(true);
      ta.setWrapStyleWord(true);
 
      // Assign the text area to a scroll pane.
      sp = new JScrollPane(ta);
      sp.setPreferredSize(new Dimension(400,200));
 
      // Invoke a generic option pane.
      op.showOptionDialog(null, sp, "File Content", JOptionPane.DEFAULT_OPTION, JOptionPane.PLAIN_MESSAGE, null, options, null); }
 
    // Test the writeFile method.  
    if (args.length > 1) {
      rwf.writeFile(args[1],rwf.readFile(args[0])); }
  }
}

You can call it like this to read and write an output.txt file from any directory:

java ReadWriteFile Fellowship.txt output.txt

It will display a JOptionDialog like this:

JavaNIO2TextFile

Any suggestions or improvements are welcome.

Written by maclochlainn

May 18th, 2014 at 12:31 pm

Posted in Java,Java 7

Tagged with , ,

Oracle 12c VARCHAR2?

without comments

The Oracle Database 12c documentation says you can set the maximum size of a VARCHAR2 to 32,767 bytes. That’s true except when you’re trying to map a large Java string to a VARCHAR2. It fails when the physical size of the Java string is greater than 4,000 bytes with an ORA-01002 or fetch out of sequence error.

SELECT read_text_file('C:\Data\loader\Hobbit1.txt')
*
ERROR at line 1:
ORA-24345: A Truncation or null fetch error occurred
 
ERROR:
ORA-01002: fetch out of sequence

You need to grant privileges before you can test this code. You can grant privileges by connecting as the SYS user of a CDB (or non-multitenant database) or as the ADMIN user of a PDB with the AS SYSDBA clause. Then, you run the following command to grant external file access to the JVM inside Oracle Database 12c:

BEGIN
  DBMS_JAVA.GRANT_PERMISSION('IMPORTER'
                            ,'SYS:java.io.FilePermission'
                            ,'C:\Data\Loader\Hobbit1.txt'
                            ,'read');
END;
/

The IMPORTER is a PDB user name, or a non-multitenant database user name. Please note that permissions must be granted on each physical file.

Here’s the code that raises the error when the external file is greater than 4,000 bytes:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
CREATE OR REPLACE AND COMPILE JAVA SOURCE NAMED "ReadFile" AS
  // Java library imports.
  import java.io.File;
  import java.io.BufferedReader;
  import java.io.FileNotFoundException;
  import java.io.IOException;
  import java.io.FileReader;
  import java.security.AccessControlException;
 
  // Class definition.  
  public class ReadFile {
    // Define class variables.
    private static File file;
    private static FileReader inTextFile;
    private static BufferedReader inTextReader;
    private static StringBuffer output = new StringBuffer();
    private static String outLine, outText;
 
    // Define readText() method.
    public static String readText(String fromFile)
      throws AccessControlException, IOException {
      // Read file.
      try {
        // Initialize File.
        file = new File(fromFile);
 
        // Check for valid file.
        if (file.exists()) {
 
          // Assign file to a stream.          
          inTextFile = new FileReader(file);
          inTextReader = new BufferedReader(inTextFile);
 
          // Read character-by-character.
          while ((outLine = inTextReader.readLine()) != null) {
            output.append(outLine + "\n"); }
 
          // Assing the StringBuffer to a String.
          outText = output.toString();
 
          // Close File.
          inTextFile.close(); }
        else {
          outText = new String("Empty"); }}
      catch (IOException e) {
        outText = new String("");
        return outText; }
    return outText; }}
/

The PL/SQL wrapper should look like this:

1
2
3
4
5
CREATE OR REPLACE FUNCTION read_text_file
(from_file VARCHAR2) RETURN VARCHAR2 IS
LANGUAGE JAVA
NAME 'ReadFile.readText(java.lang.String) return java.lang.String';
/

Then, you can query it like so:

SELECT read_text_file('C:\Data\loader\Hobbit1.txt')
FROM dual;

You can avoid the error by returning the Java file size as a CLOB data type with the following Java source code.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
CREATE OR REPLACE AND COMPILE JAVA SOURCE NAMED "ReadFile" AS
  // Java library imports.
  import java.io.File;
  import java.io.BufferedReader;
  import java.io.FileNotFoundException;
  import java.io.IOException;
  import java.io.FileReader;
  import java.security.AccessControlException;
  import java.sql.*;
  import oracle.sql.driver.*;
  import oracle.sql.*;
 
  // Class definition.  
  public class ReadFile {
    // Define class variables.
    private static int i;
    private static File file;
    private static FileReader inTextFile;
    private static BufferedReader inTextReader;
    private static StringBuffer output = new StringBuffer();
    private static String outLine, outText;
    private static CLOB outCLOB;
 
    // Define readText() method.
    public static oracle.sql.CLOB readText(String fromFile)
      throws AccessControlException, IOException, SQLException  {
      // Read file.
      try {
        // Initialize File.
        file = new File(fromFile);
 
        // Check for valid file.
        if (file.exists()) {
 
          // Assign file to a stream.          
          inTextFile = new FileReader(file);
          inTextReader = new BufferedReader(inTextFile);
 
          // Read character-by-character.
          while ((outLine = inTextReader.readLine()) != null) {
            output.append(outLine + "\n"); }
 
          // Assing the StringBuffer to a String.
          outText = output.toString();
 
          // Declare an Oracle connection.
          Connection conn = DriverManager.getConnection("jdbc:default:connection:");
 
          // Transfer the String to CLOB.
          outCLOB = CLOB.createTemporary((oracle.jdbc.OracleConnectionWrapper) conn, true, CLOB.DURATION_SESSION);
          i = outCLOB.setString(1,outText);
 
          // Close File.
          inTextFile.close(); }
        else {
          i = outCLOB.setString(1,"Empty"); }}
      catch (IOException e) {
        i = outCLOB.setString(1,"");
        return outCLOB; }
    return outCLOB; }}
/

The wrapper changes to return a CLOB and map a java.sql.CLOB as the return type of the Java library. This command works:

1
2
3
4
5
CREATE OR REPLACE FUNCTION read_clob_file
(from_file VARCHAR2) RETURN CLOB IS
LANGUAGE JAVA
NAME 'ReadFile.readText(java.lang.String) return oracle.sql.CLOB';
/

You now query the PL/SQL wrapper with this type of effective SQL*Plus command-line command:

COLUMN atext FORMAT A60 HEADING "Text"
COLUMN asize FORMAT 99,999 HEADING "Size"
 
SELECT   read_clob_file('C:\Data\loader\Hobbit1.txt') AS AText
,        LENGTH(read_clob_file('C:\Data\loader\Hobbit1.txt')) AS ASize
FROM dual;

As always, I hope this helps somebody.

Written by maclochlainn

May 7th, 2014 at 3:03 am

DBMS_JAVA Privilege Error?

without comments

It’s possible to get an error after granting privileges to an external file system. One of those errors is tedious to resolve until you understand the rules governing Java NIO file permissions.

You grant privileges to external file systems as the sys user with the grant_permission procedure of the dbms_java package, like

SQL> BEGIN
  2    DBMS_JAVA.GRANT_PERMISSION('IMPORTER'
  3                               ,'SYS:java.io.FilePermission'
  4                               ,'C:\Data\Upload'
  5                               ,'read');
  6  END;
  7  /

After you grant privileges to read, write, and delete files with Oracle’s dbms_java package, you must disconnect any active session to enjoy the new privileges. If you forget to disconnect and re-connect an active session, you get the following error message:

FROM     TABLE(list_files(get_directory_path('STAGE')))
               *
ERROR at line 2:
ORA-29532: Java CALL TERMINATED BY uncaught Java exception:
java.security.AccessControlException: Directory permissions restricted.

The problem and fix are simple. The permissions aren’t in effect until after you disconnect and reconnect your active sessions. I put this there because when I Google’d it, there wasn’t an answer already.

While I’m on the topic of privilege errors, that aren’t really errors, I thought it would be helpful to qualify how the delete permission works because I couldn’t find it anywhere in the Oracle documentation (if somebody finds it let make a comment that enriches the discussion). Unlike the read and write permissions, the delete permission requires permissions on specific files.

If you only grant permission on like:

SQL> BEGIN
  2    DBMS_JAVA.GRANT_PERMISSION('IMPORTER'
  3                               ,'SYS:java.io.FilePermission'
  4                               ,'C:\Data\Upload'
  5                               ,'read,write,delete');
  6  END;
  7  /

You would get this message when trying to delete an external file:

BEGIN
*
ERROR at line 1:
ORA-29532: Java CALL TERMINATED BY uncaught Java exception:
java.security.AccessControlException: the Permission (java.io.FilePermission
c:\DATA\log\item_import.log READ) has NOT been GRANTED TO IMPORTER. The PL/SQL
TO GRANT this IS dbms_java.grant_permission( 'IMPORTER',
'SYS:java.io.FilePermission', 'c:\data\log\item_import.log', 'read' )
ORA-06512: at "IMPORTER.DELETE_FILE", line 1
ORA-06512: at line 2

It requires that you grant permissions on individual files to have the privilege of deleting them from within Oracle. That grant would look like the following:

SQL> BEGIN
  2    DBMS_JAVA.GRANT_PERMISSION('IMPORTER'
  3                               ,'SYS:java.io.FilePermission'
  4                               ,'C:\Data\Upload\item_import.log'
  5                               ,'read,write,delete');
  6  END;
  7  /

As always, I hope this helps other developers.

Written by maclochlainn

March 29th, 2014 at 1:59 pm

Hidden DBMS_JAVA Nuance

without comments

It always happens when I’m in a hurry. Yes, I ran into one of those pesky little features with Oracle’s DBMS_JAVA package. While I try to write entries with proper GeSHi case semantics, like everyone else I tend to write PL/SQL initially in lowercase. That led me to the discovery of this wonderful error message:

BEGIN
*
ERROR at line 1:
ORA-29532: Java CALL TERMINATED BY uncaught Java exception:
oracle.aurora.vm.IdNotFoundException: importer : USER OR ROLE id does NOT exist
ORA-06512: at "SYS.DBMS_JAVA", line 705
ORA-06512: at line 2

The problem was simple, while not published, you must enter the user/schema name in uppercase text when calling DBMS_JAVA.GRANT_PERMISSION procedure. Here’s a proper example:

SQL> BEGIN
  2    DBMS_JAVA.GRANT_PERMISSION('IMPORTER'
  3                               ,'SYS:java.io.FilePermission'
  4                               ,'C:\Data\Upload'
  5                               ,'read');
  6  END;
  7  /

If you change the IMPORTER string to lower or mixed case, you raise the aforementioned error. Quite an interesting tidbit that I missed from Oracle Database 10g until Oracle Database 12c. Hope this helps you avoid wondering what’s happening when your line 2 looks like this:

  2    DBMS_JAVA.GRANT_PERMISSION('Importer'

As always, I hope this helps others. If you like more on writing Java inside the Oracle database you can check this older post.

Written by maclochlainn

March 21st, 2014 at 12:44 am

OOW & JavaOne 2013 Over

without comments

GoldenGateBridge2013Medium

Oracle OpenWorld 2013 and JavaOne 2013 are over and the America’s Cup a done deal. It was a full week. I didn’t have a moment to blog because I stay out in Livermore, which adds an hour plus to the beginning and ending of my day. It’s funny but I didn’t get a sense from some that they were excited about Oracle 12c. That’s probably because they don’t appear to know too much about it yet.

The Container Database (CDB) versus Pluggable Database (PDB) has enormous impact on how we can leverage Oracle in the private or public cloud. Admittedly, the ideas and concepts take some time to understand, implement, and appreciate.

Talking to folks, I got some great ideas for future blog posts.OOW13 If you have any that I should add, let me know with a comment. I think the first one will show everyone how to migrate traditional surrogate key primary key columns to Oracle 12c‘s new Identity Columns.

Having seen some presentations referencing zetta-bytes, I wondered to myself (and now blog readers): “When will the Exadata server be replaced by a Zettadata server?”

Up there on my list for new blog posts are Oracle 12c‘s new Invisible Columns and new DBMS_REDACT package. For those interested, I’ll also present at UTOUG’s Fall Symposium on October 29th, 2013 on SQL and PL/SQL New Features in the Oracle Database 12c.

It was great to see familiar faces and sad to note those missing. Somehow the energy in Dell’s demo ground didn’t quite replace the old Quest Software demo ground’s pizazz.

Once home, I had to pivot back to task. I’m copy editing the Oracle Database 12c Programming PL/SQL Programming book, which will release in February 2014.

If you’re wondering about the photo of the Golden Gate Bridge, my son Joseph took it with his new iPhone 5s. I’m looking forward to my own iPhone upgrade in November. ;-)

Written by maclochlainn

September 30th, 2013 at 11:55 pm

Oracle OpenWorld 2013

without comments

I registered yesterday for Oracle OpenWorld 2013, and I’ll look forward to seeing friends there. Having worked in the Oracle 12c beta for a year, I’ll be interested in the presentations. Also, hearing more about Java 7 at JavaOne. On the downside, I’m missing MySQL Connect this year.

Cloud computing offers many possibilities, and container and pluggable databases are a great solution. We’ve two new acronyms with the Oracle 12c release. A containerized database is a CDB, and a pluggable database is a PDB. I’m looking forward to seeing more about the provisioning of PDBs during the conference. If you’re new to the changes, check out CDBs and PDBs in Chapter 17 in the Oracle 12c Concepts manual.

A couple of my favorite new features are Identity and Invisible Columns. If you’re unfamiliar with the new features for application development, let me recommend this Oracle White Paper. Also, for reference I’ve covered identity and invisible columns thoroughly in the Oracle Database 12c PL/SQL Programming book, which will be available in December.

Missing the MySQL Connect 2013 Bus

Unfortunately, travel budgets preclude me attending MySQL Connect 2013 this year (alas, I’ll miss the bus). :-( It was hard because I’d like to see what’s up with MySQL (since I was a closet MySQL user at Oracle before they acquired it). Anyway, if you’re there, make sure you check out MySQL Workbench 6 for me. Also, I’d like to thank Dave Stokes for the AWESOME review he wrote on Amazon.com for my MySQL Workbench: Data Modeling & Development book. Maybe, I’ll get to go to MySQL Connect 2014 next year.

Written by maclochlainn

July 13th, 2013 at 11:34 am

Why Stored Programs?

with 2 comments

Why should you use stored programs? Great question, here’s my little insight into a situation that I heard about in a large organization.

A very large organization is having a technology argument. In someway, like politics, half-truth drives this type of discussion. This company has hundreds of databases and they’re about half SQL Server and Oracle. The argument (half-truth) states that using T-SQL or PL/SQL yields “spaghetti” code!

It seems like an old argument from my perspective. After all, I’ve been working with T-SQL and PL/SQL for a long time. Spaghetti code exists in every language when unskilled programmers solve problems but the point here is one of software architecture, and an attempt to malign stored programming in general. Let’s examine the merit of the argument against stored programs.

First of all, the argument against stored programs is simply not true. SQL DML statements, like the INSERT, UPDATE, and DELETE statements should maintain ACID compliant interactions with a single table in a database. Unfortunately, the same statements create anomalies (errors) in a poorly designed database.

Stored programs provide the ability to perform ACID compliant interactions across a series of tables in a database. They may also hide database design errors and protect the data from corruption. The same can’t be said for Java or C# developers. Java and C# developers frequently fail to see database design errors or they overlook them as inconsequential. This type of behavior results in corrupt data.

It typically raises cost, errors, and overall application complexity when key logic migrates outside the database. If you’re asking why, that’s great. Here are my thoughts on why:

  1. Making a Java or C# programmer responsible for managing the transaction scope across multiple tables in a database is not trivial. It requires a Java programmer that truly has mastered SQL. As a rule, it means a programmer writes many more lines of logic in their code because they don’t understand how to use SQL. It often eliminates joins from being performed in the database where they would considerably outperform external language operations.
  2. Identifying bottlenecks and poor usage of data becomes much more complex for DBAs because small queries that avoid joins don’t appear problematic inside the database. DBAs don’t look at the execution or scope of transactions running outside of the database and you generally are left with anecdotal customer complaints about the inefficiency of the application. Therefore, you have diminished accountability.
  3. Developing a library of stored procedures (and functions) ensures the integrity of transaction management. It also provides a series of published interfaces to developers writing the application logic. The published interface provides a modular interface, and lets developers focus on delivering quality applications without worrying about the database design. It lowers costs and increases quality by focusing developers on their strengths rather than trying to make them generalists. That having been said, it should never mask a poorly designed database!
  4. Service level agreements are critical metrics in any organization because they compel efficiency. If you mix the logic of the database and the application layer together, you can’t hold the development team responsible for the interface or batch processing metrics because they’ll always “blame” the database. Likewise, you can’t hold the database team responsible for performance when their metrics will only show trivial DML statement processing. Moreover, the DBA team will always show you that it’s not their fault because they’ve got metrics!
  5. Removing transaction controls from the database server generally means you increase the analysis and design costs. That’s because few developers have deep understanding of a non-database programming language and the database. Likewise, input from DBAs is marginalized because the solution that makes sense is disallowed by design fiat. Systems designed in this type of disparate way often evolve into extremely awkward application models.

Interestingly, the effective use of T-SQL or PL/SQL often identifies, isolates, and manages issues in poorly designed database models. That’s because they focus on the integrity of transactions across tables and leverage native database features. They also act like CSS files, effectively avoiding the use of inline style or embedded SQL and transaction control statements.

Let’s face this fact; any person who writes something like “spaghetti” code in the original context is poorly informed. They’re typically trying to sidestep blame for an existing bad application design or drive a change of platform without cost justification.

My take on this argument is two fold. Technologists in the organization may want to dump what they have and play with something else; or business and IT management may want to sidestep the wrath of angry users by blaming their failure on technology instead of how they didn’t design, manage, or deliver it.

Oh, wait … isn’t that last paragraph the reason for the existence of pre-package software? ;-) Don’t hesitate to chime in, after all it’s just my off-the-cuff opinion.

Written by maclochlainn

October 6th, 2012 at 3:48 pm

Open World 2012

with 2 comments

In prior years a daily update from Open World was possible, but this year my schedule was too full to support it. This is my compendium of thoughts about MySQL Connect, JavaOne, and Open World 2012.

MySQL Connect was great – good sessions re-enforcing the positive investments Oracle is making in the product. I’ll leave to others to qualify changes in what elements of technology are opened or closed along the road to a better MySQL. The announcement of Connector/Python 1.0 GA on Saturday was great news and as a community we owe a lot to Greet Vanderkelen.

NoSQL is a hot topic along with using JSON objects and it was interesting hearing of some unequal testing paradigms to position non-Oracle solutions to be “better” than Oracle solutions. Naturally, the MongoDB was the elephant in the room during those conversations. Some of the discussions seemed more like political rants than technical dialog. A great spot to start with NoSQL and JSON would be downloading Oracle’s MySQL 5.6 Release Candidate.

There were also more PostgreSQL conversations this year and fairly accurate comparisons between it and Oracle or MySQL from folks. It certainly looks like it may gain more ground.

Java 7 is awesome, and my favorite feature is clearly NIO2, reinforced at JavaOne. NIO2 brings static methods to interactions with external directory and file sources. It removes directories from the files class, which is long overdue. The nature of those static methods also happen to fit within the definition of Java code that lives inside the Oracle database and gives me a whole host of thoughts about potential in Oracle Database 12c.

Larry Ellison’s keynote was impressive because it gives us a clear vision of Oracle’s direction and Duncan Davies captured the keynote well in his blog. The continued presence of Red Hat and VMWare offers interesting reality checks to their key contributions to world wide implementation of the Oracle technical stack.

Issues that seem most critical to those I’ve chatted with are storage, security, tools, and development languages. A nice update on security can be found in the new edition of Hacking Exposed 7: Network Security Secrets & Solutions (7th Edition).

On the forthcoming Oracle 12c release, Information Week just released a good summary view. The introduction of the R programming language on the Exadata Server leads me to wonder about what uses may magically appears in Oracle Enterprise Manager down the road. The TIOBE Index for September 2012 doesn’t list the R language in the top 20 programming languages but there’s always the future. No mention of Erlang programming language at any of the conferences that I caught but it’s inevitably on the horizon as application servers evolve.

Now we wait for the Oracle Database 12c release, which looks like something in the very short term. Perhaps right after the holidays …

Written by maclochlainn

October 4th, 2012 at 12:30 pm

SQL Developer JVM Fix

with 5 comments

It’s amazing the moving parts in Oracle Database 11g, and the ones that I don’t use after installation for a while often reach out to teach me something new. That’s what happened when I went to launch SQL Developer on my Windows 7 Professional 64-bit installation.

I got the message Unable to find a Java Virtual Machine, as shown in the image below. It really means unable to find a 32-bit Java 5 or Java 6 (1.6.0_4+) SDK home. Although the installation appeared fine, it pointed the SQL Developer configuration file to an incompatible 64-bit Java 7 SDK.

You fix this error by following these steps:

  1. Open the sqldeveloper.conf file and check the SetJavaHome parameter value. You find the sqldeveloper.conf file in the following directory:
%ORACLE_HOME\sqldeveloper\sqldeveloper\bin
  1. Install the 32-bit Java 6 (1.6.0_4+) SDK on the operating system if not installed already. You can check whether it’s installed by looking for it in the Program Files (x86) folder.
  2. Change the value of the SetJavaHome parameter to point to the new 32-bit Java 6 home directory (or folder). The following change to line 18 in the sqldeveloper.conf file should fix it on your installation (provided that’s your version of the JVM).
18
SetJavaHome C:\Program Files (x86)\Java\jdk1.6.0_34

Hope this helps those who run into the same issue.

Written by maclochlainn

August 15th, 2012 at 6:01 pm