Cannot retrieve data from a remote table quering any field

[smicloud]

We have created a remote table and it works fine, the table is populated with data. 

I can't find all information about how the remote table logic works. When we want to query the table using normal GlideRecord we can only do it for a couple of fields but not all. I.e. sys_id and just another custom field (which happens to be the display value). 

1. The first question is about the functionality of remote tables. Is it not possible to use .addQuery on any field? If not, what is the rule?

2. Also, is object_id reserved in some way when using remote table? 

3. This might overlap with 1: Is there any general limitations using GlideRecord? If I want to query 'ID1', following doesn't work: 

gr.addQuery('sys_id', 'IN', 'ID1,ID2');

but following works: 

gr.addQuery('sys_id', 'ID1');

[GlideFather]

Hi @smicloud,

please provide more details about the remote tables and overall configurations

[smicloud]

Unfortunately I am not allowed to copy anything of the configuration. That's why my questions are quite general and I think it should be possible to answer them as is.