Hi Junwang,
>
> I'm looking at the catalog definition, I have some questions which
> might be silly.
Thanks for your interest in SQL/PGQ.
>
> Each pg element can have multiple labels(whose properties belong
> to the same pg element), can we have multiple elements share the
> same label?
Yes. A label can be shared between edges and vertices as well.
>
> If we have a 1..* relation between element and label, I think maybe
> we don't need _pg_propgraph_label_.
pg_propgraph_label is used to map a label name in a given property
graph to its OID. pg_propgraph_element_label - can be used to find all
the elements with a given label and all the labels of a given element.
The relationship is many to many.
>
> From the name _pg_propgraph_label_property_, I tend to think it is
> referencing _pg_propgraph_label_, but actually it is referencing
> _pg_propgraph_element_label_.
>
Right.
--
Best Wishes,
Ashutosh Bapat
