Partition database between users and implement disk quotas

Hello,<br /><br />I wrote an aplication where I store data from different users whithin the same database. There is no
linkbetween data of different users.<br /><br />In my current implementation, I added a column "user_id" in each table,
and,with views and rules mechanisms, I am able to hide data from other users. Everything works fine and I am happy with
thissolution. But I now have another need : I would want to measure the disk usage of each user such that I can
restrictthe access to the database when a user exceeds its limit.<br /><br />I envisaged three solutions to solve this
problem,but I do not know which one would be the best : <br /><br />Solution1 : keep the same database layout, and
countthe size of each record of a user. As some columns have variable sizes, this is not a really simple solution. And
Ihave no idea on how to take into account index and stuff like that. I am not sure this solution is feasible and, if
yes,I fear it will not be efficient to compute disk usage on this way.<br /><br />Solution 2 : use a separate database
foreach client. This solution is probably the simplest one. But, one of the advantage of my previous solution was that
Iwas able to use connection pool to connect to my database as all users are using the same database with same db user
(accessis provided via a web service). With this solution, this will no more be possible: I will need a dedicated
connectionfor each user. A second problem I am fearing is that I have a lot of clients (several hundreds) and I am not
surethis is a good idea to create so much database on the same server.<br /><br />Solution 3 : use the table
partitionningmechanism. I never used this feature, but from what I read in the doc, it seems that I could use this
mechanismto put data from different clients in different partitions. As each partition is a dedicated sub-table, I
supposeI could use dedicated postgresql mechanism to compute its size (including associated index and so on). I really
thinkthis solution is well fitted to my need. The only thing that I fear is that I don't know if it's a good idea to
partitiona table in hundreds of different partitions ?<br /><br />So, does someone has good advices to solve my problem
?Maybe there is another solution that I am not aware of ?<br /><br />Thanks in advance for your help,<br />Brice<br />