<p>I have this doubt, I've searched the web and the answers seem to be diversified. Is it better to use mysql_pconnect over mysql_connect when connecting to a database via PHP? I read that pconnect scales much better, but on the other hand, being a persistent connection... having 10 000 connections at the same time, all persistent, doesn't seem scalable to me.</p>

<p>Thanks in advance.</p>

It's very unlikely that you'll reach 10000 connections. Anyhow, go to the
official source
. (Emphasis mine).
If persistent connections don't have
  any added functionality, what are 
  they good for?
The answer here is extremely simple --
  efficiency. Persistent connections are
  good if the overhead to create a link
  to your SQL server is high. Whether or
  not this overhead is really high
  depends on many factors. Like, what
  kind of  database it is, whether or
  not it sits on the same computer on
  which your  web server sits, how
  loaded the machine the SQL server sits
  on is and so  forth.
The bottom line
  is that if that connection overhead is
  high,  persistent connections help you
  considerably
. They cause the child
  process  to simply connect only once
  for its entire lifespan, instead of
  every  time it processes a page that
  requires connecting to the SQL server.
  This means that for every child that
  opened a persistent connection will 
  have its own open persistent
  connection to the server. For example,
  if you  had 20 different child
  processes that ran a script that made
  a persistent  connection to your SQL
  server, you'd have 20 different
  connections to  the SQL server, one
  from each child.
Note, however, that this can have some
  drawbacks if you are using a  database
  with connection limits that are
  exceeded by persistent child 
  connections. If your database has a
  limit of 16 simultaneous connections, 
  and in the course of a busy server
  session, 17 child threads attempt  to
  connect, one will not be able to. If
  there are bugs in your scripts  which
  do not allow the connections to shut
  down (such as infinite loops),  the
  database with only 16 connections may
  be rapidly swamped. Check your
  database documentation for information
  on handling abandoned or  idle
  connections.