anchor.diff:  
   (defmacro with-pj-conn (() &body body)
     `(pomo:with-connection *connection*
  -     ;; There is a small overhead for this, see (alter-role-set-search-path)
  -     ;; for a more permanent solution.
  +     ;; We only need to set the search path for DEFINE-JSON-QUERY,
  +     ;; see below.  There is a small overhead for this, see
  +     ;; (alter-role-set-search-path) for a more permanent solution.
        (pomo:set-search-path *default-search-path*)
        ,@body))
   
  
positive.code: 
    (with-input-from-file (stream *human-file*)
      (with-model-transaction ()
        ;; We need empty arrays to go in as empty arrays, not empty
        ;; lists (ie. nil) so that :jsonb-array-length can work (see below).
        (loop for human across (yason:parse stream :json-arrays-as-vectors t)
              do (pj:insert 'human human)
  
negative.code:   (:select 'jdoc ;; 'jdoc is the generic name for the JSON column in all models
     :from 'human
  
     ;; Our 'jdoc column is Postgres type jsonb.
     ;; j-> is sugar for Postgres operator -> which returns a top level
     ;; key in jdoc as Postgres type jsonb.  Thus we apply jsonb
     ;; functions to it...
     :where (:and (:or (:@> 'jdoc filter))                     ;; Postgres json 'containment' op
                  (:= (:jsonb-array-length (j-> "friends")) 1) ;; Postgres jsonb function
                  (:~ (j->> "email") email-regex))))           ;; Postgres regex function
  