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    How important is it to get the right file_list_size in $data_root prof_library?

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

    Description:
    In Aleph, is there a way to tell the size of the library as created at the very beginning? By size, I mean "Demo", "VSMALL", "SMALL", "MEDIUM", and etc. The reason why I am asking this questions is for the concerns of scalability in future.

    For example, if a Bib library is created as "medium-sized" at the beginning, and when the number of records in the database/library exceeds a million down the road, will that entail any drastic measure such as recreating a large database? Or it can be easily addressed by just adding more tablespace and data files? I am not sure if this is an issue, and hence the inquiry.

    Resolution:
    As seen in the $aleph_root/tab/file_list.BIB, the MEDIUM allocation for the z00 is 128M, while the LARGE allocation is 960M.

    In Oracle 9-up (Aleph 16-up), these file_list sizes are of no real significance.

    It used to be that a table was limited to 505 extents (see, for example KBs 4004 and 4132), but the default specification in Oracle 9-up is "unlimited".

    Also, in Oracle (unlike IBM's old VSAM), the number of extents does *not* affect performance: a table with 500 128M extents performs just as well as a table with 70 960M extents.

    See also KB 16384-36802 which suggests some ranges of numbers.


    • Article last edited: 10/8/2013
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