If you want to find out the information in the vCenter database, the VMware support bundle comes handy. For example, if you want to analyze the event history, task history, you can dig out these information from the support bundle. By default, the vCenter support bundle is collected as part of the VMware support bundle on standalone client, but not on the vSphere Web Client. So make sure to mark the check box if you want the vCenter info.
As @lamw documented in his blog, you can access the database in the vCenter software appliance (vCSA). In the first appliance of version 5.0, VMware included IBM DB2 Embedded and then switched to vPostgres right after. That’s because vPostgres is VMware’s own product based on the open source Postgres.
By default, the access to the vPostgress database is limited to local applications. In other words, if you want to access the database remotely, it will not work. After researching a little, I figured out how to configure the databse for remote access.
I haven’t written Java code to access relational database for a while. Over the years there have been lots of progresses, especially with various Object Relational Mapping (ORM) frameworks. With these frameworks, accessing relational databases becomes pretty easy. In some cases, you don’t have to know SQL at all. Of course understanding SQL is always an advantage.
After playing with the vCenter appliance simulator feature documented by William, I got into a show stopper that vCenter service (VPXD) could not be started. I don’t think it’s related to the simulator feature at all. My guess is that it’s caused by a sudden power off of the virtual machine but didn’t try to reproduce the problem that way – I care more to fix it than anything else.