ORA-00932: inconsistent datatypes: expected - got CLOB

As I am doing data query with distinct syntax in select clause, I got this error message:
ORA-00932: inconsistent datatypes: expected - got CLOB

This error message result from Clob limitation:

1. CLOBs don't work like strings. You can't ask for the LENGTH of a CLOB column, for example. You can work around this with PL/SQL calls but it isn't much fun.
2. LOBs are not allowed in GROUP BY, ORDER BY, SELECT DISTINCT, aggregates and JOINS

Therefore, I re-designed my database schema. Save this CLOB column into another table.

ORA-01502 Oracle Index in Unusable State

As I execute sql statement to do search, it return this message unexpectedly:ORA-01502: index 'RSDB.RESUME_PK' or partition of such index is in unusable state

Solution: rebuild this index

ALTER INDEX RESUME_PK REBUILD

After I executed this rebuild action, it turned out to be normal.

Reference
[1] http://www.mydigitallife.info/2006/01/28/ora-01502-oracle-index-in-unusable-state/

Template method pattern example

http://www.slideshare.net/junyuo/template-method-pattern-example

Utilize Quartz to Implement Scheduling Service

Scenario


Implementation Process


http://www.slideshare.net/junyuo/utilize-quartz-to-implement-scheduling-service

PMD

PMD scans Java source code and looks for potential problems like:

• Possible bugs - empty try/catch/finally/switch statements
• Dead code - unused local variables, parameters and private methods
• Suboptimal code - wasteful String/StringBuffer usage
• Overcomplicated expressions - unnecessary if statements, for loops that could be while loops
• Duplicate code - copied/pasted code means copied/pasted bugs

It can be plug-in to Eclipse, NetBeans, etc.

http://pmd.sourceforge.net/

Utilize Jericho HTML Parser to Resolve NCR Problem

Agenda

• What is NCR (Numeric Character Reference) ?
• Scenario Description
• Problem (XML with NCR)
• Resolution Process
• Result (NCR had been decoded)
  

http://www.slideshare.net/junyuo/utilize-jericho-html-parser-to-resolve-ncr-problem

XML Utility: Convert DTD to XML Schema

http://www.hitsw.com/xml_utilites/