drop table if exists refid;
drop table if exists comment_attr;
drop table if exists descr_attr;
drop table if exists text_attr;
drop table if exists text_attr;
drop table if exists attribute;
drop table if exists doctag;
drop table if exists docuse;
drop table if exists knowelm;
drop table if exists knowtype;
drop table if exists contributor_rel;
drop table if exists converts_rel;
drop table if exists cycle_rel;
drop table if exists stamp_rel;
drop table if exists usedby_rel;
drop table if exists uses_rel;
drop table if exists versions_rel;
drop table if exists relation;
drop table if exists cycle;
drop table if exists document;
drop table if exists entity;
drop table if exists projext;
drop table if exists stamp;
drop table if exists file;
drop table if exists doctype;
drop table if exists scenario;
drop table if exists study;
drop table if exists contelm;
drop table if exists contype;
drop table if exists users;
drop table if exists role;
--drop table if exists persistent_id;
drop table if exists text;
