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Displaying posts with tag: common (reset)
common_schema booth on Percona Live 2013

common_schema booth in Percona Live 2013 (someone left their soup on our table)

Allen Kinnard

Yay! I got a booth!

I confess it was mostly deserted. My hero Allen Kinnard, whom I've never met before, was kind enough to volunteer to occupy the booth.
So between him and me, both of course also looking to visit other booths and talk to people, the common_schema booth was only moderately attended.

Well, this was the DotOrg Pavilion: free booths for free & open source projects (e.g. OpenStack, PhpMyAdmin, etc.).
We both did our best to explain common_schema to the visitors.

The booth was actually titled "common_schema & openark-kit". However I don't …

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[MySQL] Deleting/Updating Rows Common To 2 Tables – Speed And Slave Lag Considerations

Introduction

A question I recently saw on Stack Overflow titled Faster way to delete matching [database] rows? prompted me to organize my thoughts and observations on the subject and quickly jot them down here.

Here is the brief description of the task: say, you have 2 MySQL tables a and b. The tables contain the same type of data, for example log entries. Now you want to delete all or a subset of the entries in table a that exist in table b.

Solutions Suggested By Others

DELETE FROM a WHERE EXISTS (SELECT b.id FROM b WHERE b.id = a.id);
DELETE a FROM a INNER JOIN b on a.id=b.id;
DELETE FROM a WHERE id IN (SELECT id FROM b)

The Problem With Suggested Solutions

Solutions above are all fine if the tables are quite small and the …

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c,mm,n - Open Source defining the future of Mobility

Today was at the faculty of Industrial Design in Delft to attend the first 'c,mm,n Garage' event. c,mm,n - pronounced as common - is a project to develop sustainable mobility. It is led by Stichting Natuur en Milieu, The Netherlands Society for Nature and Environment and currently the main participants are students from a number of Dutch technical universities.

Right now, engineering efforts are focused on a clean, remanufacturable car that runs on electricity generated by a hydrogen fuel cell:
The car is almost completely built out of biodegradable plastics, making it extremely light and environmentally friendly.
There is a YouTube Video available that shows off the exterior design and which gives you a good impression of how open and …

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