How may databases are allowed to host in a given MySQL server? e.g. 4
or 5

Will performance suffer If I install too many DB in a single server?

Thanks.

howa wrote:
That depends how many your database administrator has limited you to. I
can't find the exact limit in the manual, but it will handle far more
than you will ever need. Probably way more than thousands.

Cheers,
Nicholas Sherlock

--
http://www.sherlocksoftware.org

Nicholas Sherlock ¼g¹D¡G

how to limit?

Nicholas Sherlock wrote:

users could create more in the same server.

howa ¼g¹D¡G

some background information...

we have a limited set of user, say. 500, they have many rows (e.g. avg.
more than 10000 rows stored on a table, so num of row = 5000000, and
the number still increasing, what i am think is stored the data in
different database per user, so each user owned a set of tables, the
scablity of the system can be greatly increased.

but i want to know the exact limit of the number of DB.

howa wrote:
I don't know the limit in MySQL, but you'll run out of system resources
long before you'll run out of databases. 500 is piddly.

As to performance suffering - insufficient information. There are too
many variables involved. Your best bet is to test it yourself.

Whether you *should* break up your database into 500 separate ones is
another question (which you didn't ask).

--
==================
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.
jstucklex (AT) attglobal (DOT) net
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"howa" <howachen (AT) gmail (DOT) com> wrote


As you will have gathered by other replies, there doesn't seem to be a
"fixed" answer and in fact why should there be a fixed answer. It's more
likely that the limitation would be the specification of the machine you're
using for the server.

Consider ISP's that provide MySQL databases as part of the hosting packages.
My ISP only provides me with two databases, but multiply that by the number
of clients they have and you will soon realise that they must have thousands
per server.

SA

Sean ¼g¹D¡G

What I think is:

MySQL should have a limit anyway, just as max data length, max row
size, etc.

but no one know and can't find in the doc.

try this:

$i=0;
$n=20;
mysql_connect();
for($n=0;$n>20
{
$i++;
$res=mysql_query('create database databse'+$i);
if(!$res)$n=21;
}



if program runs sucessfully u ll get u r answer but be careful i m not
responsible for nay problem(;-))

What I think is:

MySQL should have a limit anyway, just as max data length, max row
size, etc.

but no one know and can't find in the doc.

--------

There are some limitations published for MySQL, as follows:

Database size: described only as multiple gigabytes or single terabytes

Number of columns in one table: 3398

Size (data) of a table row (excluding BLOB and TEXT): 65534

Number of tables: "unlimited" - up to 32 indexes per table with 256 bytes
maximum key length and there is an equation which calculates that there is a
maximum (implied by other limitations) somewhere in the region of 4 billion

Given the bit about unlimited number of tables, would 'guess' that it's
probably the same for databases per server.

SA