Does that headline sound fishy? Actually, Diff and Merge (WinMerge, to be exact) were my last resort in this disaster scenario. The final outcome could be told quite shortly, though this scenario serves as a good example how Murphy might hit you anytime… but first things first:
This is more a note to myself in case I’ll encounter a similar environment. But maybe it helps others – at least my search results weren’t suitable to Windows in the first place.
C:\> set ORACLE_HOME=C:\path\to\grid\home
C:\> set ORACLE_SID=+ASM1
connected to an idle instance.
Some troubles — especially those happening only sporadically — are not so easy to shoot and call for a deeper understanding of the matter. In the following real-world example this means: SQL*Net Tracing and some knowledge about the inner workings of the server’s operating system, particularly random number generation.
This case was suited well to demonstrate an approach to trouble-shoot connections to Oracle databases.