Yeah, the last couple of months have been pretty bad for some customers, but reading the DreamHost blog description of exactly what happened and the steps being taken to rectify the situation, I am confident that DreamHost have everything under control now and hopefully we never see a recurrence.
In general, before the problems, uptime has been good here at DreamHost, not perfect, but better than most low-cost hosting. My sites rarely went down, and when they did they were usually back up before I could lodge a support request.
I believe there is a timeout for processes, but I am not sure this applies to PHP, at least I have never had such a PHP timeout affect any of my scripts.
You have full access to .htaccess files here at DreamHost, just create the file and drop it into the relevant directory.
As far as php.ini, you do not have write access to the php.ini for the default PHP install. However, you can create a local install of PHP and edit the php.ini file to your hearts content. All the relevant instructions for doing so are in the wiki.
phpMyAdmin is available by default on all MySQL databases. Simply browse to dbname.domain.com
Not that I am aware of.
While there may be a memory size limit for PHP, I am not aware of one and have never encountered a problem running various scripts.
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