The correct per pool parameter is reserve_pool. The global parameter is named
reserve_pool_size.
While at it, document reserve_pool parameter.
Set maximum size of pools for this database. If not set,
the default_pool_size is used.
+reserve_pool
+------------
+Set additional connections for this database. If not set, reserve_pool_size is
+used.
+
connect_query
-------------
;forcedb = host=127.0.0.1 port=300 user=baz password=foo client_encoding=UNICODE datestyle=ISO connect_query='SELECT 1'
; use custom pool sizes
-;nondefaultdb = pool_size=50 reserve_pool_size=10
+;nondefaultdb = pool_size=50 reserve_pool=10
; use auth_user with auth_query if user not present in auth_file
; auth_user must exist in auth_file