ext-rep file naming

[Peter Dobcsanyi]

Dear All,

We are going to have hundreds of ext-rep files floating around in our
system. To make this situation manageable I recommend the introduction
of an "ext-rep file naming convention". The purpose of such a scheme is
twofold. On one hand, it makes the system administration and the
organization of data processing (including external contributions) much
easier. On the other hand, it can serve as a base for a simple but
nevertheless useful web presentation method. This means that we can put
our design collections online within a few days and long before the
"real" design database actually comes alive.

My proposal for ext-rep file naming follows. Before the details, let's
start with an example. An ext-rep file file which contains the Fano
plane can be named:

   t2-v7-b7-r3-k3-L1.icga.xml.gz 

An ext-rep file's name has the following structure:

    parameter_section[.content_indicators].type[.compression_type]

    parameter_section:

        Describe the parameters of the designs in the given file over
        the parameter domain of t,v,b,r,k,L, where L stands for lambda.
        The format is xN-...  where x is one of the parameter's symbol
        and N is the constant value of the parameter within the file. If
        some of the parameters are not relevant to the given list of
        designs and/or are not constant then they are left out.

    content_indicators:         (optional)

        One letter symbols to indicate which of the subtrees of a
        <block_design> tree are present for each block design in the
        file. The possible values:

            i   <indicators>
            c   <combinatorial_properties>
            g   <automorphism_group>
            r   <resolutions>
            s   <statistical_properties>

        It is not required that any of the indicated subtrees is fully
        expanded.

        Finally there is a special indicator:

            a   indicates that all pairwise non-isomorphic designs
                of the given parameters are present in the file.

    type:

        xml     for XML ext-rep
        sex     for Lisp S-expressions

    compression_type:           (optional)

        gz      gzipped file
        bz2    

As you know each design should have a ID. This ID is created from the
"parameter_section" of the file name by appending '-N' where N is a
serial number within the file starting 0. (Note, we use 0-based indexing
elsewhere in the ext-rep.)

For the time being, we should arrange our design collection (i.e.
ext-rep files) in a simple and logical directory structure, like:

    designs/
        t-designs/
        ...

Some remarks are due to place the proposed naming into the correct
perspective:

    - This naming scheme is not a replacement for the database and it
      cannot (should not) provide the same level of consistency. In
      particular, the IDs won't be necessarily unique.

    - There can be overlaps between files, that is OK.

    - Although it is human readable, the more important design aim
      behind it was to be able to parse/process/search this system by
      simple automatic tools.


Please comment,

--             ,
    Peter Dobcsanyi