The database is not that big, it will be more or less... 51MB I suppose.
Both databases are accessible from the same user.
The destination database, at the beginning of this process, will be empty.
About the first possibility, that I presume is the best I have:
I will investigate the meaning of triggers and what are queue tables. I do have a first question here:
Will this work when we have different database schemas (understanding by this, the fact that, the column and tables names are different between databases)?
On inserting, since the destination database will be empty, the ID's will be equal on all tables on both databases.
Later on the process, if some records are deleted on the original database, they should we deleted as well on the destination database. The inverse process will not be required but, if we do it, we will get the ID's correspondence on both databases. If I see this correctly.
According to this new informations a) and b), if you believe something could be done differently, please, let me know, so that I can properly investigate more for this subject.
Thank you both, again,