Db2 for z/OS EXPLAIN: What an Access Path Is, and What it Would Be

The EXPLAIN functionality of Db2 for z/OS, by which the query optimizer's access path determinations are externalized, has been around as long as I can remember, and Db2 people, by and large, are familiar with the concept. In recent weeks, however, I discovered that...

Db2 for z/OS CHAR versus VARCHAR, Part 2 – a DBA’s Story

Last month, I posted to this blog an entry in which I provided my thoughts on the CHAR (fixed-length) versus the VARCHAR (varying-length) data type for character string columns in Db2 for z/OS tables. Soon after, I received a note from a longtime Db2 for z/OS DBA...

Db2 for z/OS Character Columns: Thoughts on CHAR versus VARCHAR

Recently, I received from a Db2 for z/OS DBA a question: for a table column that will hold character string values, are there any recommendations concerning the use of CHAR (fixed-length) versus VARCHAR (variable-length) for the column's data type?That question has...