Server side cursor limitations for on demand loading of data in query tool [RM2137] [pgAdmin4]

Hi Dave,

To implement feature #2137 <https://redmine.postgresql.org/issues/2137> we'll
need to use server cursor. However server cursor has some
limitation.
For eg.
1. It cannot execute BEGIN; query (basically user cannot start new database
transaction)
2. In case if Auto commit is true then we try to execute user queries
inside BEGIN and END when ever it's possible even though user has not put
BEGIN and END in his query.

Also not all queries executed using Query tool produces records as result.
So can we assume only
queries started with SELECT should be executed using server cursor to
support on demand loading.
Or should we give user an option to use on demand loading like we have
options for Auto commit? and Auto rollback?
In case of on demand loading option user will be responsible to execute
correct queries (queries which can be executed using server cursor)

Let me know your opinion on this.

--
*Harshal Dhumal*
*Software Engineer*

EnterpriseDB India: http://www.enterprisedb.com
The Enterprise PostgreSQL Company