Do you recommend using handle in each function using database?

[gnusupport]

At first I have made libraries that connect and fetch and handle was &optional. If there was no handle standard *db* handle was used. Programs could access one database.

Then I have developed separate Emacs package that uses the same database but due to its nature could also use separate database and other databases outside of my local computer.

As then I had 2 programs connecting to local database and complexities arrive in future when using multiple databases in the same time, I am of opinion that each call to function that uses database should also transfer the handle, so that handle is not just global variable.

Do you agree on this?

Handle was here optional and it worked well until I started making two connections to database:

(defun rcd-sql (sql &optional handle)
  "Sends SQL queries to PostgreSQL database and returns results"
  (let ((handle (if handle handle *cf*)))
    (condition-case err
	(pq:query handle sql)
      (error
       (if (string-match "^ERROR:  syntax error" (cdr err))
	   (progn
	     (if (fboundp 'speak) (speak (cdr err)))
	     (message (cdr err)))
	 ;; re-throw
	 (signal (car err) (cdr err)))))))

(defun rcd-sql-list (sql &optional handle)
  "Returns list of lists instead of vectors"
  (let ((list '()))
    (dolist (i (apply 'rcd-sql (list sql handle)) (reverse list))
      (cond ((eq (type-of i) 'vector) (push (append i '()) list))
	    (t (push i list))))))

(defun rcd-sql-first (sql &optional handle)
  "Returns first entry from SQL query"
  (car (apply 'rcd-sql (list sql handle))))

My opinion is that I should not make it optional but require handle each time. Is that what you also recommend?