 comment on column people_taxonomic_names.person_name is 'Person name for the group concerned';
 create table chronostratigraphy
        (
+        id serial not null,
         eon_ref classifications_ids,
         eon_indexed classifications_names,
         era_ref classifications_ids,

comment on column my_saved_specimens.modification_date_time is 'Last update date and time';
create table template_classifications
       (
        id serial not null,
        name varchar not null,
        name_indexed varchar not null,
        description_year smallint,
        description_year_compl char(2),
        level_ref integer not null,
        status status default 'valid' not null,
        path varchar default '/' not null
       );
comment on table template_classifications is 'Template table used to construct every common data in each classifications tables (taxonomy, chronostratigraphy, lithostratigraphy,...)';
comment on column template_classifications.id is 'Unique identifier of a classification unit';
comment on column template_classifications.name is 'Classification unit name';
comment on column template_classifications.name_indexed is 'Indexed form of name field';
comment on column template_classifications.description_year is 'Year of description';

comment on column mineralogy.unit_variety_indexed is 'Indexed name of sub level the current unit depends of';
create table lithology
       (
        id serial not null,
        constraint pk_lithology primary key (id),
        constraint unq_lithology unique (path, name_indexed),
        constraint fk_lithology_catalogue_levels foreign key (level_ref) references catalogue_levels(id)
