Friday 19 November 2010

Removing Phantom Indexes



Whilst working on resolving a phantom index issue, John Godfrey from Carys Computing came across a useful little trick for removing the rogue index.

Faced with an unwanted phantom index on a table in his application, John turned to the database manager and diving into the Utilities -> Indexes menu, he ran the option to remove the phantom index. However, nothing happened, the phantom index remained.

John then tried to add the index so that he could then remove it. As expected, OpenInsight duly reported that the new index could not be added as one already existed – the phantom index.

John notes that, at this point, you can turn to the help system in OpenInsight. This points you towards the System Editor, in which you can change field 6 from a 1 to a 0, to indicate that no BTree index is active.

However, John has found a neat, quick resolution to the phantom index issue and one that he asked me to share with everyone through my blog. He states:

“To the errant field add an XRef Index. This magically makes the Index editable and removable. So go back in and remove the XRef and BTree Indexes as required.”

I would like to thank John for this contribution and I will welcome any more tricks like this that anyone comes across and who would like to share with my readers.

Thursday 4 November 2010

O4W and older browsers.



OpenInsight for the Web (O4W) is fast becoming, if not already is, Revelation’s leading web development tool. This is no surprise when you see just how easy it is to create Web 2.0 compliant browser based systems against OpenInsight’s own Linear Hash data, TigerLogic’s D3 data, Rocket Software’s U2 data and also SQL data stores – the latter 3 via the built in dedicated data connectors.

However, being fully Web 2.0 compliant does come at a small cost. O4W uses advanced web technologies to deliver an interactive and dynamic web experience. To fully benefit from this, users and developers should use the most current versions of their web browser. At the time of writing this blog posting, these versions include; Chrome 3, Firefox 3, IE8, Opera 9 and Safari 3.

However, that is not the be all and end all. Developers and users may chose to use older versions of their web browser, but at the risk of reduced functionality. Developers who choose to support these older browsers should undertake their own careful testing of any plug-ins and functionality that their web solutions may rely upon. Minimally acceptable browser versions currently include Chrome 1+, Firefox 2+, IE6+, Opera 9+ and Safari 3+.

As a default, users accessing an O4W based system with an older browser will be presented with a message that their browser is unsupported. They can continue, but the message remains at the top of the O4W forms as a reminder that something might not work totally as expected. This can be seen if you run the Online O4W demo in an older browser or with IE8 running in compatibility mode.

The good new though, is that the javascript to create and display this message is stored in the O4W configuration record and this functionality will be updateable via the O4W Maintenance/Config Records screen in version 1.1 and later.

However, for the moment (version 1.0) developers can disable or modify the message by editing the appropriate CFG_O4W record in the O4WCONFIG table and clearing out or changing field 45 as appropriate. This can be either ‘CFG_O4W’ globally, or *CFG_O4W for a specific application.

Updating this will be easier from O4W version 1.1 (to be included in OpenInsight 9.2.1). From version 1.1, O4W will have an updatable field via the DB Management, O4W Maintenance, configuration Records, Browsers Tab.

Partial content c/o http://www.revelation.com/ discussion forum.