http://www.itjungle.com/fhg/fhgindex.html Tips, Advice and Code. en-us 2010 Guild Companies, Inc. All Rights Reserved March 17, 2010 IT Jungle IT Jungle http://www.itjungle/com/fhg/fhg-rss.html 20 http://www.itjungle.com/images/fhg/title_fhg.gif http://www.itjungle/com/fhg/fhg-rss.html 275 50 http://www.itjungle.com/fhg/fhg031710-story01.html DB2 for i supports the concept of union, which creates or derives a single result set table by combining two other result set tables, each of which was derived from a SELECT statement or another UNION. (See the discussion on cascading unions at the end of this article). A union is very useful when an SQL query must operate on two or more tables where JOIN cannot be used to produce the desired result set table. http://www.itjungle.com/fhg/fhg031710-story01.html March 17, 2010 http://www.itjungle.com/fhg/fhg031710-story02.html Using global data (fields, variables and constants) is generally considered to be poor programming practice. One reason is that a subroutine or subprocedure that uses global data is not easily placed into service elsewhere. Another reason is that undesirable side effects may occur when one routine changes a variable that another routine uses. However, in some situations global data makes sense. I would like to provide one example. http://www.itjungle.com/fhg/fhg031710-story02.html March 17, 2010 http://www.itjungle.com/fhg/fhg031710-story03.html My i/OS system performance hasn't been very good lately and my storage usage is starting to shoot up. I'm thinking I should IPL my System i 550 box to reset the system. Will an IPL help me regain storage and improve performance? http://www.itjungle.com/fhg/fhg031710-story03.html March 17, 2010