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From:Brian Aker Date:July 4 2009 3:55pm
Subject:Re: How to recover from online DDL failure?
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Hi!

On Jul 4, 2009, at 8:04 AM, Ingo Strüwing wrote:

> If the data dictionary is in the engine, how do you know, which engine
> serves a certain table?

Engines are asked in order, with the default being first, about who  
has the table (assuming it is not already in the TableShare cache).  
The default implementation is only called once (aka... backup DFE for  
engines which lack a dictionary).

Seeing how the vast majority use just one engine the hit cost is  
practically the same as having just one centralized system. Toss in  
the relatively few numbers of tables compared to the size of the  
TableCache and... you never see a issue.

At some point the cache itself will be pushed down for the engine to  
be able to handle as well, this allows a greater degree of ability for  
online operations.

Cheers,
	-Brian
Thread
How to recover from online DDL failure?Yuan Wang3 Jul
  • Re: How to recover from online DDL failure?MARK CALLAGHAN3 Jul
    • Re: How to recover from online DDL failure?Brian Aker3 Jul
      • Re: How to recover from online DDL failure?Ingo Strüwing4 Jul
        • Re: How to recover from online DDL failure?Brian Aker4 Jul