Re: Proposed Windows-specific change: Enable crash dumps (like core files)

On 4/10/2010 8:06 PM, Andrew Dunstan wrote:
>
>
> On 10/04/2010 07:50 AM, Craig Ringer wrote:
>>
>> - If the crash dump handler is enabled by setting the GUC,
>> all backends register the handler during startup or (if it
>> proves practical) when the GUC is changed.
>>
>> - When the handler is triggered by the OS trapping an unhandled
>> exception, it loads dbghelp.dll, writes the appropriate dump
>> format to the hardcoded path, and terminates the process.
>>
>>
>
> What is the performance impact of doing that? Specifically, how does it
> affect backend startup time?

Without testing I can't say for sure.

My expection based on how the handler works would be: near-zero, about
as expensive as registering a signal handler, plus the cost of reading
the GUC and doing one string compare to test the value. When disabled,
it's just the GUC test.

Is there a better mechanism to use for features that're going to be
unused the great majority of the time? Perhaps something that does
require a server restart, but doesn't have any cost at all when disabled?

--
Craig Ringer

Tech-related writing at http://soapyfrogs.blogspot.com/