• Article Type: General
• Product: Aleph
• Product Version: 20, 21, 22, 23

Description:
We are curious if there is a limit to the number of item records which can be attached to a single record. Or, perhaps there are recommendations for what the maximum number should be.

We have a few titles which have numerous items attached to them and which have begun to cause problems in our Web OPAC. In addition, we know of a couple of titles which are about to be barcoded which will have over 2000 item records each. Please advise us as to what limit (if any) should be placed on creating item records off of one record.

Resolution:
The "theoretical" limit is based on the item sequence in the z30 table: Since the system does "000010", "000020", etc., 999,999 items could be linked to each ADM record.

However, as you have seen, the problem arises in retrieving long lists of items and sorting them.

This can be an issue in both the Web and the GUI....

* The Web:

Prior to version 16.02 the system always built a display of all items on the Holdings screen. This was problematic. Some titles would take several minutes; others would time out and could not be displayed at all.

With version 16 the "setenv www_no_items_display" in www_server.conf was introduced. This limits how many items the system will try to display before stopping and issuing a message (such as, "Display of items is limited to xxxx.... Try setting a filter (year, library, volume." )

Some sites have found that increasing the timeout let certain titles which had been a problem display OK.

Also, eliminating "PRE" checking for the Request button has speeded up display in some cases.

* The GUI:

The display of the Items List in the GUI does not seem to have been as much of a problem as the Web. The system builds the display for only about 100 items at a time. As you click the down arrow, it builds more. You can change the sort so the items you want are nearer to the top.

{ I find these display times for USM records in Acq/Serials:

USM50 000006556 1036 items 10 seconds
USM50 000015476 1096 items 15 seconds
USM50 000006412 4576 items 40 seconds

Subsequent redisplays in same session are about 50% faster. }

The overview tree will load only 800 lines. If you have more items than this, catalogers will not be able to move the higher-numbered records to a different bib...