Create a staging_items staging table to hold the holdings data:

CREATE TABLE staging_items (
        l_callnum text, -- call number label
	hseq int, 
        egid  int,  -- biblio.record_entry_id
        createdate      date,
        l_location        text,
        l_barcode         text,
        l_circ_modifier   text,
        l_owning_lib      text  -- actor.org_unit.shortname
);

Import the items using the HOLDINGS.pg SQL script created using the extract_holdings utility.

psql -U evergreen -f HOLDINGS.pg evergreen

the file HOLDINGS.pg and/or the COPY query may need to be adjusted for your particular circumstances.

Generate shelving locations from your staging table.

INSERT INTO asset.copy_location (name, owning_lib)
SELECT  DISTINCT l.location, ou.id
FROM  staging_items l 
       JOIN actor.org_unit ou	ON (l.owning_lib = ou.shortname); 

Generate circulation modifiers from your staging table.

INSERT INTO config.circ_modifier (code, name, description, sip2_media_type, magnetic_media)
        SELECT  DISTINCT l_circ_modifier AS code,
          l_circ_modifier AS name,
          LOWER(l_circ_modifier) AS description,
          '001' AS sip2_media_type,
          FALSE AS magnetic_media
          FROM  staging_items
          WHERE l_circ_modifier NOT IN (SELECT code FROM config.circ_modifier);

Generate call numbers from your staging table:

INSERT INTO asset.call_number (creator,editor,record,label,owning_lib)
SELECT  DISTINCT 1, 1, egid, l.callnum, ou.id
FROM  staging.staging_items l
JOIN actor.org_unit ou ON (l.owning_lib = ou.shortname);

Generate copies from your staging table:

INSERT INTO asset.copy (
circ_lib, creator, editor, create_date, barcode,
STATUS, location, loan_duration, fine_level, circ_modifier, deposit, ref, call_number)		

SELECT  DISTINCT ou.id AS circ_lib,
	1 AS creator,
	1 AS editor,
	l.l_createdate AS create_date,
	l.l_barcode AS barcode,
	0 AS STATUS,
	cl.id AS location,
	2 AS loan_duration,
	2 AS fine_level,
	l.l_circ_modifier AS circ_modifier,
	FALSE AS deposit,
	CASE
	WHEN l.l_circ_modifier = 'REFERENCE' THEN TRUE
	ELSE FALSE
	END AS ref,						
	cn.id AS call_number
	FROM  staging_items l
		JOIN actor.org_unit ou
			ON (l.l_owning_lib = ou.shortname)
		JOIN asset.copy_location cl
			ON (ou.id = cl.owning_lib AND l.l_location = cl.name)
		JOIN metabib.real_full_rec m 
			ON (m.record = l.egid)
		JOIN asset.call_number cn
			ON (ou.id = cn.owning_lib  
			AND m.record = cn.record       
			AND l.l_callnum = cn.label)      

You should now have copies in your Evergreen database and should be able to search and find the bibliographic records with attached copies.