Dynatrace will not recognize transactions on DB when you will install agent only on DB host. Such informations are recorded on application endpoint (ado.net, jdbc, php pdo etc). You should install agent there.
Installing on DB host only will give you informations about hosts and maybe process performance without transactions. You can also write plugin which will take additional metrics from your DB but you will never catch transactions there.
I don't think that any exist now but it's quite easy to develop using Dynatrace tools:
Here is good article about that, there is also a link to some examples of plugins that are included in dynatrace. You can use them as starting point 🙂
I didn't find openldap in supported technology so I'm afraid not. As I said, those extra metrics can be acheaved via plugin (for example for mssql you will se deadlock, pagelife etc). But this will be not transaction metrics. But If you have application process that is communicating with this DB i it possible that you will see DB transactions from application end (as I've said previously).
To get transaction data (PurePaths) it would be necessary to instrument the OpenLDAP manually by the Dynatrace SDK. This is almost certainly achievable but will require a decent C knowledge and you will need to use your custom build of OpenLDAP.
I don't know your environment and situation, I don't think it worth the effort.
With OneAgent plugins, you can get just metrics, but no individual transactions.
You can read more here:
I've read more about open LDAP and actually there is like Julius said. If you will compile your own build of OpenLDAP and instrument using tools from dynatrace you should be able to see transactions. But it is really hard work to do if you don't know the actual code of app and has to create revere engineering.
You have to distinguish between OneAgent SDK and OneAgent plugins.
Plugins are written in Python and you are able to collect custom metrics using the Python code and push the metrics to monitored processes (or host).
SDK is in fact a library that you need to use in the code of your monitored application. It enables you capture transactions, remote calls, etc. So basically the transaction data.
For SDK it is essential that you understand the application code to be able to insert the SDK calls where necessary. Also, keep in mind you will need to use your customized build of the application. It's definitely a long journey to success.