• Article Type: General
• Product: Aleph
• Product Version: 18.01

Description:
In many of our records we have both subfield a and z in the 035 field. I have the OPAC set to find OCLC numbers. This works when there is only a subfield a in the 035 field. When there is also a subfield z, in addition to a, I get no results searching for the OCLC number.

I've tried making changes to the 035 line in tab11_ind, but cannot search for records where both subfields are evident. I re-index using p-manage-05 after making changes.I currently have tab11_ind set to: 035 OCLC az

How do I retrieve records where both subfields have an OCLC number in the 035 field?

Resolution:
Direct indexes don't work in the same way as keyword indexes, which generally index each subfield (as well as each word within a subfield) as a separate entity. Direct indexes build a single entity for whatever you designate. So if you say to index the entire field, $$a and $$z are indexed as one single entity. Here is the internal structure of the entry for the first bib you cited in the OCLC direct index:

02 z11_text .........$$a(OCoLC)70192283$$z(OCoLC)171120683

There is a way to created individual 'virtual' fields for separate subfields when building a direct index. I see that this has been done in your environment. Here are the relevant lines in tab11_ind:
a035 035
z035 035

The two virtual fields (a035 and z035) are generated by another table - tab_expand_extract.

So if you change the index being used in your OPAC from OCLC to 035, I think you will find this problem resolved. Let me know the results.

• Article last edited: 10/8/2013