linerad = 10px
linewid *= 0.5
$h = 0.21
C0: circle radius 10%
arrow 2*arrowht
T1: box "table-or-subquery" fit
arrow right linerad then down $h then right linewid+linerad
OP: box "join-operator" fit
arrow 2*arrowht
T2: box "table-or-subquery" fit
arrow 2*arrowht
JC: box "join-constraint" fit
arrow right linewid then up even with C0 then right linerad+arrowht
circle same
# bypass
arrow from T1.e right even with T2
line to arrowht west of last circle
# Loop
arrow from JC.e right linerad then down even with $h below JC \
then left even with T2
line left even with linerad+arrowht west of OP.w \
then up even with OP then to OP.w