Documentation Source Text

Check-in [e1613cdf0f]
Login

Many hyperlinks are disabled.
Use anonymous login to enable hyperlinks.

Overview
Comment:Tweaks to the most-widely-deployed page.
Timelines: family | ancestors | descendants | both | trunk
Files: files | file ages | folders
SHA1: e1613cdf0f7c177868be40d30ce2ec10777e483d
User & Date: drh 2007-12-15 14:29:28
Context
2007-12-15
14:44
Updates to the distinctive features page. check-in: ceb449161d user: drh tags: trunk
14:29
Tweaks to the most-widely-deployed page. check-in: e1613cdf0f user: drh tags: trunk
14:18
Add justification to the claim of being the most widely deployed SQL database engine. check-in: 0f6b8d5492 user: drh tags: trunk
Changes
Hide Diffs Unified Diffs Ignore Whitespace Patch

Changes to pages/mostdeployed.in.

3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
..
23
24
25
26
27
28
29
30
31

32
33



34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
..
61
62
63
64
65
66
67
68
69
70
71
72
73
74
<h2>Most Widely Deployed Database</h2>

<p>We <em>believe</em> that there are more copies of SQLite
in use around the world than any other SQL database engine,
and possibly all other database engines combined.  We cannot
be certain of this since we have no way of measuring either
the number of SQLite deployments nor the number of deployments
of other databases.</p>

<p>The belief that SQLite is the most widely deployed SQL
database engine stems from its use as an embedded database.
Other database engines, such as MySQL, PostgreSQL, or Oracle,
are typically found one to a server.  And usually a single
server can serve multiple users.  With SQLite, on the other
hand, a single user will typically have exclusive use of
................................................................................

<p>At the end of 2006, there were 100 million websites on the internet.
<a href="http://news.netcraft.com/archives/2006/11/01/november_2006_web_server_survey.html">[1]</a>
Let us use that number as a proxy for the number of deployed
SQL database engines other than SQLite.  Not every website
runs an SQL database engine.  Larger websites run multiple
database engines.  But the vast majority of smaller websites
(the long tail) if they use database engine at all, share
a database engine with several other websites running off

of the same host.  Hopefully these two factors roughly cancel
each other out.</p>




<p>Now let's consider where SQLite is used:</p>

<ul>
<li>125 million copies of Mozilla Firefox 
<a href="http://arstechnica.com/news.ars/post/20071202-mozilla-coo-over-125-million-people-use-firefox.html">[2]</a></li>
<li>20 million Mac computers, each of which contains multiple
copys of SQLite</li>
<li>20 million websites run PHP which has SQLite built in.  
<a href="http://www.php.net/usage.php">[3]</a>  We have no
way of estimating what fraction of those sites actively use
SQLite, but we think it is a significant fraction.<li>
<li><a href="http://www.skype.com/">Skype</a> has been downloaded
300 million times and has 100 million registered users
<a href="http://skypejournal.com/blog/archives/2006/04/how_many_users_does_skype_have_today.php">[4]</a>.  All recent versions of the Skype
client use SQLite internally.</li>
<li>20 million Symbian smartphones shipped in Q3 2007
<a href="http://www.symbian.com/news/pr/2007/pr20079552.html">[5]</a>
Newer versions of the SymbianOS have SQLite built in.  It is unclear
exactly how many Symbian phones actually contain SQLite, so we will
use a single quarter's sales as a lower bound.</li>
................................................................................
This has not been publicly acknowledged by the manufactures
but it is known to the SQLite developers.</li>
<li>There are perhaps millions of additional deployments of
SQLite that the SQLite developers do not know about.</li>
</ul>

<p>
By these rough estimates, we see 200 or 300 million SQLite deployments
and about 100 million deployments of other SQL database engines.  These
estimates are obviously rough may be off significantly.  
But there is a wide margin. So the SQLite
developers think it is likely that SQLite is the most widely deployed
SQL database engine in the world.
</p>







|







 







|
|
>
|
<
>
>
>







|




|
|







 







|

|




3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
..
23
24
25
26
27
28
29
30
31
32
33

34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
..
64
65
66
67
68
69
70
71
72
73
74
75
76
77
<h2>Most Widely Deployed Database</h2>

<p>We <em>believe</em> that there are more copies of SQLite
in use around the world than any other SQL database engine,
and possibly all other database engines combined.  We cannot
be certain of this since we have no way of measuring either
the number of SQLite deployments nor the number of deployments
of other databases.  But we beleave the claim is defensible.</p>

<p>The belief that SQLite is the most widely deployed SQL
database engine stems from its use as an embedded database.
Other database engines, such as MySQL, PostgreSQL, or Oracle,
are typically found one to a server.  And usually a single
server can serve multiple users.  With SQLite, on the other
hand, a single user will typically have exclusive use of
................................................................................

<p>At the end of 2006, there were 100 million websites on the internet.
<a href="http://news.netcraft.com/archives/2006/11/01/november_2006_web_server_survey.html">[1]</a>
Let us use that number as a proxy for the number of deployed
SQL database engines other than SQLite.  Not every website
runs an SQL database engine.  Larger websites run multiple
database engines.  But the vast majority of smaller websites
(the long tail) share
a database engine with several other websites,
if they use database engine at all
Hopefully these two factors cancel

each other out and give 100 million as a reasonable estimate
for the number of non-SQLite SQL database engines currently
deployed.</p>

<p>Now let's consider where SQLite is used:</p>

<ul>
<li>125 million copies of Mozilla Firefox 
<a href="http://arstechnica.com/news.ars/post/20071202-mozilla-coo-over-125-million-people-use-firefox.html">[2]</a></li>
<li>20 million Mac computers, each of which contains multiple
copies of SQLite</li>
<li>20 million websites run PHP which has SQLite built in.  
<a href="http://www.php.net/usage.php">[3]</a>  We have no
way of estimating what fraction of those sites actively use
SQLite, but we think it is a significant fraction.<li>
<li>300 million downloads of the <a href="http://www.skype.com/">Skype</a>
client software and 100 million registered users
<a href="http://skypejournal.com/blog/archives/2006/04/how_many_users_does_skype_have_today.php">[4]</a>.  All recent versions of the Skype
client use SQLite internally.</li>
<li>20 million Symbian smartphones shipped in Q3 2007
<a href="http://www.symbian.com/news/pr/2007/pr20079552.html">[5]</a>
Newer versions of the SymbianOS have SQLite built in.  It is unclear
exactly how many Symbian phones actually contain SQLite, so we will
use a single quarter's sales as a lower bound.</li>
................................................................................
This has not been publicly acknowledged by the manufactures
but it is known to the SQLite developers.</li>
<li>There are perhaps millions of additional deployments of
SQLite that the SQLite developers do not know about.</li>
</ul>

<p>
By these estimates, we see 200 or 300 million SQLite deployments
and about 100 million deployments of other SQL database engines.  These
estimates are obviously very rough and may be off significantly.  
But there is a wide margin. So the SQLite
developers think it is likely that SQLite is the most widely deployed
SQL database engine in the world.
</p>