"Can we have more helicopter views?" asked a client from whom we're running a series of courses - by which they mean overviews that put all the elements of the technologies in place on a diagram - showing how tomcat relates to MySQL and how JBoss and Struts and EJBs fit in to the picture. For sure you can, and I note the term "Helicopter views" to add to my dictionary of metaphors.

"Do you have any Scots in the group?" I ask my class, as I use another Metaphor to explain how MySQL's select command restricts the returned values to just a tiny subset of the data available. If you have a tartan where 20% of the warp threads are green, and where 20% of the weft threads are green, then your cloth has only 4% of its area being full green - green on green. Translate that into a Select command; if you choose just a fifth of the columns in a table, and you then use a where clause where just 20% of the rows are selected, your result set, efficiently, is just 4% of the data held.

(written 2006-04-06, updated 2006-06-05)

 S157 - More MySQL commands
  [158] MySQL - LEFT JOIN and RIGHT JOIN, INNER JOIN and OUTER JOIN - (2004-12-20)
  [159] MySQL - Optimising Selects - (2004-12-21)
  [279] Getting a list of unique values from a MySQL column - (2005-04-14)
  [449] Matching in MySQL - (2005-09-24)
  [494] MySQL - a score of things to remember - (2005-11-12)
  [502] SELECT in MySQL - choosing the rows you want - (2005-11-22)
  [513] MySQL - JOIN or WHERE to link tables correctly? - (2005-12-01)
  [515] MySQL - an FAQ - (2005-12-03)
  [517] An occasional chance, and reducing data to manageable levels - (2005-12-04)
  [567] Combining similar rows from a MySQL database select - (2006-01-17)
  [572] Giving the researcher power over database analysis - (2006-01-22)
  [581] Saving a MySQL query results to your local disc for Excel - (2006-01-29)
  [591] Key facts - SQL and MySQL - (2006-02-04)
  [1213] MySQL - the order of clauses and the order of actions - (2007-06-01)
  [1235] Outputting numbers as words - MySQL with Perl or PHP - (2007-06-17)
  [1331] MySQL joins revisited - (2007-09-03)
  [1574] Joining MySQL tables revisited - finding nonmatching records, etc - (2008-03-15)
  [1735] Finding words and work boundaries (MySQL, Perl, PHP) - (2008-08-03)
  [1904] Ruby, Perl, Linux, MySQL - some training notes - (2008-11-23)
  [2110] MySQL - looking for records in one table that do NOT correspond to records in another table - (2009-03-31)
  [2259] Grouping rows for a summary report - MySQL and PHP - (2009-06-27)
  [2448] MySQL - efficiency and other topics - (2009-10-10)
  [2643] Relating tables with joins in MySQL - (2010-02-21)
  [2644] Counting rows in joined MySQL tables - (2010-02-22)
  [2645] Optimising and caching your MySQL enquiries - (2010-02-22)
  [2647] Removing duplicates from a MySQL table - (2010-02-22)
  [3061] Databases - why data is split into separate tables, and how to join them - (2010-11-20)
  [3270] SQL - Data v Metadata, and the various stages of data selection - (2011-04-29)
  [4481] Extracting data from backups to restore selected rows from MySQL tables - (2015-05-01)

A100 - Web Application Deployment - The Components of a Web-Based Solution
  [34] Linux / LAMP course - (2004-08-31)
  [49] Business is the predominant user of Tomcat, Perl and Tcl - (2004-09-15)
  [166] Acronyms - (2005-01-02)
  [367] Ajax - (2005-07-03)
  [433] FTP - how to make the right transfers - (2005-09-01)
  [442] How far away is that server? - (2005-09-10)
  [510] Dynamic Web presence - next generation web site - (2005-11-29)
  [924] The LAMP Cookbook - Linux, Apache, MySQL, PHP / Perl - (2006-11-13)
  [1176] A pu that got me into trouble - (2007-05-04)
  [1198] From Web to Web 2 - (2007-05-21)
  [1265] Apache, Tomcat, Jakarta, httpd, web server - what are they? - (2007-07-13)
  [1496] PHP / Web 2 logging - (2008-01-06)
  [2099] Should I maintain the programming code on my own website? - (2009-03-23)
  [2896] LAMP - Linux, Apache, MySQL, PHP - install, configure, administer - (2010-07-30)
  [3891] The components of an Apache httpd / Tomcat / MySQL stack and what each does - (2012-10-13)

A099 - Java Application - Deployment on the Web
  [576] Why run two different web servers - (2006-01-25)
  [659] Web Application Components - (2006-03-28)
  [1621] Linux and Java Course in London - (2008-04-24)
  [2130] Javascript - move cursor over image to change a different image. - (2009-04-16)
  [2599] Telling Apache web servers apart / notes for the non-technical - (2010-01-26)

Back to Keeping your regular expressions simple

Previous and next or Horse's mouth home

Forward to Wiltshire to get an extra MP

Sympathetic development
Melksham, Wiltshire
Adding PHP tags to an old cgi program
Wiltshire to get an extra MP
Helicopter views and tartans
Keeping your regular expressions simple
Both ends of the animal
Architectural Heritage - Devizes
The best Open Source library in town
Python - block insets help with documentation