>> Why would delay_key_writes require a table rebuild? It's not
>> modifying the data. Reloading tens of millions of rows for several
>> hours seems to be a waste of time.
It probably flips a bit in the .frm file or something like that, but I
have not investigated it myself.
My guess is that you can "hack" this to do what you want. We wrote
about this in our book -- you can alter ENUM lists without a table
rebuild, for example. I'm betting you can do the same thing here.
Rather than describe the whole thing let me show you the blog post
Aurimas wrote about it:
http://www.mysqlperformanceblog.com/2007/10/29/hacking-to-make-alter-table-online-for-certain-changes/
Baron
--
Baron Schwartz, Director of Consulting, Percona Inc.
Our Blog: http://www.mysqlperformanceblog.com/
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