Subject Re: [Firebird-Java] How to change forced writes settings via JayBird?
Author Alec Swan
Is there any way to override these settings in my test environment beside
changing them in Are there any API I can call or system
or environment variables I can set to accomplish that?



On Mon, Oct 12, 2009 at 7:22 PM, Helen Borrie <helebor@...> wrote:

> At 11:35 AM 13/10/2009, you wrote:
> >Can anybody explain the reason why ForcedWrites is a database property and
> >MaxUnflushedWrites is a server property given that the later is only used
> >when the former is set?
> MaxUnflushedWrites is a parameter that dictates the server's interaction
> with the operating system, not the server's interaction with databases. It
> is only applicable to databases that have ForcedWrites off, which is about
> the server's interaction with that particular database. It's more "usual"
> than "unusual" to have FW on for all databases. It's normally a temporary
> usage for a database that's about to undergo a huge batch operation, since
> it can allow such operations to go faster.
> FW is not something to disable lightly. On Windows particularly,
> asynchronous write adds a high level of risk of corruption that is otherwise
> absent. FW is of no help whatsoever in improving performance that is slow
> due to inefficient metadata structures or indexing, inefficient queries,
> heavy garbage buildup, inappropriate cache size, inadequate system
> resources, overlooked index maintenance, etc. etc. - hence Roman's comment
> that you interpreted as "sarcastic".
> Helen

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