Non-numeric search on numeric index causing OPAC to hang

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

Description:
Searching in the Advanced Search screen of the OPAC you can force it to hang up by feeding it nonsense. For instance, if you do an OCLC Number search for something non-numeric, like the terms "purple monkey dishwasher", it will just sit there for awhile and then give you a blank screen (Firefox) or a The page cannot be display error message (IE).

We have dug to find out why this is happening and we believe it to be because the PNO (OCLC index) goes through filing routine 95 to parse the search string. Filing routine 95 strips all non-numeric data, leaving a null search string (when no numbers are included).

Is a "null search string" possible? If so does it require reindexing?

Although normally you would not put it in non numerics in the OCLC search, but there are alot of users that do that...

Resolution:
Although there are cases where users enter letters in an "OCLC number" search, the inclusion of letters along with numbers does *not* cause this problem. It is only when the user enters only letters and *no* numbers. I would think that that would be quite rare.

I describe some things to do below, but you may want to do *nothing* since I think it would be rare and the consequence is not so bad. (They just enter a new search.)

This shows that there are 258 PNO index entries with blank keys:

SQL-ABC01> select count(*) from z11 where z11_rec_key like 'PNO %';
**** Hit return to continue ****

COUNT(*)
----------
258

You could do the following to delete them:

SQL-ABC01> delete from z11 where z11_rec_key like 'PNO %';

If that doesn't help, I find that USM01 does not have this problem. (USM01 has some blank Z11 rec_keys but they don't have this problem.)

The usm01 tab_filing has a "95 non_numeric" line like the odn01, but it is not actually used (that is, it is not referenced in tab00.eng).

Instead, the following entry is used:

21 del_subfield
21 compress -
21 compress_blank
21 cut_prefix

The "cut_prefix" will eliminate the "(OCoLC)" or "ocm" preceding the number.

You could try that -- running p_manage_05 to regenerate the z11.

• Article last edited: 10/8/2013