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Implicit Conversion And ORA-01722

I’ve an email from a reader that he gets ORA-01722 error from a query. he says that the query works well on same structured tables on different schemas. After a short conversation, I figured out that it’s about implicit conversion mechanism.

Let’s create a sample table to demonstrate the problem:

You may notice that we use “varchar” column to keep “number” values. That was the exact case my reader faced.

Let’s write a simple query:

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Oracle 11g New Feature: RMAN Data Recovery Advisor

In Oracle 11g, RMAN provides a new advisor called Data Recovery Advisor (DRA). DRA has several new commands to help DBAs for performing recovery tasks.

To list of database failures, you can issue:

DRA will consolidate related failures into a single failure. You can list a failure individually by issuing “list failure X detail” command.

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Optimum Size of The Online Redo Log Files

The Oracle Database Performance Tuning Guide recommends switching logs at most once every twenty minutes. If our online redo logs switch once every 10 minus during peak hours, our redo logs should be increased to 2 times larger then their current size.

Here’s a simple query for calculating recommended size of redo log files:

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How to Develop Java Stored Procedures

I’ll try to demonstrate how we can use loadjava to load our Java class into Oracle Database and use its methods as stored procedures. Before we begin to write the Java codes, I’ll create a simple table. When I call my java stored procedure, it will insert a record to this table.

I created this table in HR schema because I’ll load my java object in HR schema. If you’ll use another schema, then do not forget to load your java code in same schema or set required permissions. This is the main method I’ll use as my stored procedure:

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How to Upgrade Oracle Application Express (APEX)

Upgrading APEX is a very easy task. All we need to install the new APEX version to the database. Only one instance of Application Express can be active in the database so when we run the APEX installation script, it will detect existing APEX installation and upgrade it.

Then we need to update the /i/ (virtual directory) with the images, javascript, css, etc. For the standard HTTP Server installations, you can use copy command. If you use Embedded PL/SQL Gateway (EPG), you need to run apxldimg.sql script.

After the upgrade, you may need to modify some applications but most of them will work correctly. APEX also provides a utility to upgrade your applications and make them use the latest features.

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