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Loop length recommendations

  • Article Type: General
  • Product: Aleph
  • Product Version: 20

Description:
I would like some guidelines for loop length settings.
From what I can see in the prof_library, the loop names have changed and there are more of them. While I might be able to guess many of these, I'd rather have more direct information.

Resolution:
The symbolic names for setting loop length in the various batch processes have been changed to match the explicit program names. So, for example, if you are running p-manage-01 to build the keyword index, the associated loop length (indicating how many records should be process in a each cycle) is now called “p_manage_01_loop_length”..
You only need to be concerned about those loop lengths associated with batch jobs that you actually run. Here is a list of loop length variables sites run most commonly, and their associated functions:

p_arc_01_loop_length – Extract Aleph information to ARC
p_arc_01_time_loop_length – Extract Aleph information to ARC
p_arc_01_bor_loop_length – Extract Aleph information to ARC
p_manage_01_loop_length – Update Keyword Index
p_manage_02_loop_length – Update Browse Index
p_manage_05_loop_length – Update Direct Index
p_manage_07_loop_length – Update Short Bib Records
p_manage_12_loop_length – Create Links Between Records
p_manage_16_loop_length – Alphabetize Headings - Setup
p_manage_27_loop_length – Update Sort Index
p_manage_32_loop_length – Build Counters for Logical Bases
p_manage_35_loop_length – Update Brief Records
p_manage_62_loop_length – Update Item Records
p_manage_102_loop_length – Pre-Enrich Bibliographic Headings based on the Authority Database
p_manage_103_loop_length – Trigger z07 Records
p_manage_180_loop_length – Load Catalog Records – Parallel Load
p_ret_01_loop_length – Retrieve Catalog Records
p_ret_adm_03_loop_length - Advanced General Retrieval Form
p_union_02_loop_length – Populate Equivalencies Table (for Union View)

The 3% guideline discussed in section 3.2 (Adjust the “cycle size” parameters) of the “How to Open a Library” document is still a good starting point for tuning these variables. But the final determination should take into account how much sort space you have allocated, how much temporary space is available for intermediate files, and how many concurrent cycles you specify on each individual job.
Another very good source of information on estimating optimal cycle size on batch jobs is the document “How to Run Index Jobs”. Refer to the section “What Cycle Size?”

Keywords: _loop_length

Additional Information

See also, Article 000025510 ("Optimal cycle size / number of processes for indexing jobs").


  • Article last edited: 1/15/2015