Metacat

/*

 * We need to drop constraint(subject, relationship, object) and create new

 * new (docid, subject, relationship, object). Unfortunately, progres doesn't

 * remove the constrain directly and we should create a new one and copy the

 * old data to new one, then rename them.

 */

ALTER TABLE xml_relation RENAME TO old_xml_relation;

DROP INDEX xml_relation_pkey;

/*DROP SEQUENCE xml_relation_id_seq;

*CREATE SEQUENCE xml_relation_id_seq;

*/

CREATE TABLE xml_relation (

        relationid INT8 default nextval('xml_relation_id_seq') PRIMARY KEY,

                                             -- unique id

        docid VARCHAR(250) ,         -- the docid of the package file

                                             -- that this relation came from

        packagetype VARCHAR(250),          -- the type of the package

        subject VARCHAR(512) NOT NULL, -- the subject of the relation

        subdoctype VARCHAR(128),                -- the doctype of the subject

        relationship VARCHAR(128)  NOT NULL,-- the relationship type

        object VARCHAR(512) NOT NULL, -- the object of the relation

        objdoctype VARCHAR(128),          -- the doctype of the object

        CONSTRAINT xml_relation_uk1 UNIQUE (docid, subject, relationship, object),

        CONSTRAINT xml_relation_docid_fk1

                FOREIGN KEY (docid) REFERENCES xml_documents

);

INSERT INTO xml_relation SELECT * FROM old_xml_relation;