Smart text trimming procedure in PostgreSQL

smartTextCutting.sql

CREATE OR REPLACE FUNCTION th.prc_th_rate_titles_create()
  RETURNS integer AS
$BODY$
DECLARE
    p_title VARCHAR := '';
    p_sql VARCHAR := '';
    p_item RECORD;
    total_rows INTEGER := 0;
BEGIN    
    p_sql := 'SELECT id, comment, title FROM th.th_rates';

    FOR p_item IN EXECUTE p_sql 
        LOOP
            IF char_length(p_item.title) = 0 THEN
		IF char_length(p_item.comment) > 60 THEN
		    p_title = substring(p_item.comment for 61);
		    IF p_title !~ E'\\W$' THEN
	                p_title = regexp_replace(p_title, E'\\M(\\W)+\\s*\\S*$', '');
                    END IF;
			
		    p_title = regexp_replace(p_title, E'\\M(\\s*(\\W|за|до|для|под|из|от|то|к|у|о|но|от|по|на|не|с|а|и|в|\\d)+)*\\s*$', '', 'i');

		    IF char_length(p_title) > 60 THEN
			p_title = substring(p_title for 60);
	            END IF;
		ELSE
		    p_title = regexp_replace(p_item.comment, E'\\M(\\W)+\\s*\\S*$', '');
		END IF;

                IF char_length(p_item.comment) != char_length(p_title) THEN
                    p_title = p_title || '...';
                END IF;
		        
		UPDATE th.th_rates SET
		    title = p_title
		WHERE id = p_item.id;  

		total_rows := total_rows + 1;
            END IF;
        END LOOP;

   RETURN total_rows;
END;
$BODY$
  LANGUAGE plpgsql VOLATILE
  COST 100;
ALTER FUNCTION th.prc_th_rate_titles_create()
  OWNER TO developer;