Interesting post from Senior Tech guru at Yahoo! Venu Anuganti:

 How many serversNumber of DBAsHow many web serversNumber of caching serversVersion of MySQLLanguage, platformOperating System
MySQL

1 M, 3 S

1/10

2

2

5.1.23

Perl,php and bash

Linux fedora

Sun

2 clustered, 2 individual

1.5

160+

8

5.0.21

Lots of stuff (java mostly)

Open Solaris

Flickr

166

At present 0

244

14

5.0.51

Php and some Java

Linux

Fotolog

140 databases on 37 instances

10 instances a DBA

70

40 ( 2 on each, 80 total)

4.11 and 4.4

Php, 90% Java

Solaris 10

Wikipedia

20

None, but everybody is kind of a DBA

70+200

40 ( 2 on each, 80 total)

Â

Php, c++, python

Fedora / Ubuntu

Facebook

30000 databases, 1800 db servers

2

1200

805

5.0.44 with relay log corruption patch

Php, python, c++ and erlang

Fedora / RHEL

Youtube

I can not say

3

I can not say

I can not say

5.0.24

Python

SuSE 9

See the # of Facebook servers? (Directly from MySQL conference panellists – read rest of post here). Vaguely interesting for even non-geeks I think… (hat tip Craig Bailey who thinks that As of April Facebook apparently uses 1800 MySQL servers, 1200 web servers, 2 DBAs, hmmm… seems low”)