ue_01 slow (after load of "ebrary" records)

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Article Type: General
Product: Aleph
Product Version: 18.01

Description:
The ue_01 process on Production is going at about at about 20% of its usual rate. We loaded 10,000 records for ebooks yesterday and the z07 count is still very high this morning (at 6:31 it was over 7700).

Why is is running so slowly? I don't see any errors in the logs.

Resolution:
Aside from absence of Oracle indexes or the presence of Oracle Statistics, the factors which can affect ue_01 speed are:

the number of indexable fields in the incoming records
the expands specified in the xxx01/tab/tab_expand (especially the WORD section of tab_expand)
the number of indexes being built (especially Word indexes)
the number of fields being sent to the indexes (especially Word indexes)

I see that there are many, many more "Update z98 from z980" lines in today's ue_01 logs than in previous logs. Basically, today's logs have an average of 3 "Update z98"s for each "HANDLING DOC", while the logs from previous days have an average ratio of 0.3 "Update z98"s for each "HANDLING DOC".

This is an increase of roughly 10 times.

Checking a random doc (001402755) in util f/1/28, which shows the Word indexing, and comparing it to other docs I find that many Word-indexed fields are repeated in these records:

533 $$aElectronic reproduction.$$bPalo Alto, Calif. :$$cebrary,$$d2005.$$nAvai
lable via World Wide Web.$$nAccess may be limited to ebrary affiliated libraries

655 7 L $$aElectronic books.$$2local
7102 L $$aebrary, Inc.

85640 L $$uhttp://www.linccweb.org/webscripts/ebooks.asp??bookid=EB10001777$$yClick
here to view this eBook. Access is restricted to valid borrowers.

910 L $$xDo not edit or delete this field.$$aEB10001777

TYP L $$aEB$$bElectronic Book
TYP L $$aCF$$bComputer File
TYP L $$aER$$bElectronic Resource

This causes the same words to be sent to the same index, causing many z980's to be created for the words, and resulting in more "Update z98 from z980"s.

Please see KB 8192-2168 for a discussion of the z98/z980 relationship. And KB 8192-3080 for a somewhat similar case.

KB 8192-4135 describes a rep_change which was done for v18 which allows a site to increase the treshold for "Update z98 from z980" from 90 to 900. If you will be doing other large loads of ebooks, you may want to consider this.

See also KB 16384-57697 for additional discussion of ue_01 slowness.

Article last edited: 10/8/2013