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Re: What's the '--quick' meaning in mysqldump?
Posted by: feng guo
Date: June 02, 2014 08:30PM

Rick James Wrote:
-------------------------------------------------------
> Yeah, "quick" is a confusing option. Here's an
> explanation of the two methods that can be used
> for a SELECT. Note: mysqldump is effectively
> doing SELECTs to fetch the data.
>
> Plan A:
> Ask the server for all the rows, collect them in a
> buffer in mysqldump, then write them to the output
> file.
>
> Plan B:
> Ask the server for the rows a few at a time, as
> they arrive, write them to output.
>
> Generally, you can't tell the difference between
> these two schemes.
>
> For small, or even medium sized tables, it does
> not matter.
>
> For tables with many millions of rows:
> Plan A could run out of RAM.
> Plan B would start writing sooner, but might (or
> might not) take longer to finish.
>
> I think the confusion has to do with which part it
> "quick". A better term would be "stream" or
> "buffer" or something closer to what it is doing.

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Re: What's the '--quick' meaning in mysqldump?
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June 02, 2014 08:30PM


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