RDM Dictionary field lengths

Piotr Gorazdowski
Piotr Gorazdowski Newcomer
in TREP APIs

Hi,

What exactly do the "LENGTH" and "RWF LEN" represent in RDM Dictionary file.

Is it amount of characters a field can have, is it field dependent and what is the best approach to setting up those values.

Is there any specific document describing each field type and its maximum values.

If the TREP service is RWF type the "LENGTH" column is not applicable, correct?

Thanks

Piotr

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Best Answer

  • zoya faberov
    zoya faberov ✭✭✭✭✭
    Answer ✓

    Hi @Piotr Gorazdowski,

    "LENGTH" in the dictionary is the maximum length of the corresponding string, i.e. length of 1234567,89 would be 10. This length allows a consumer to understand, parse and absorb the data.

    However, if you are writing a custom publisher, I would suggest to review RDM Usage Guide, section Field Dictionary, subsection Field Type Keywords, to gain an in-depth understanding of the field types that can be defined, with the corresponding possible lengths, and to design your custom fields to be conformant with the model:

    image

    as well.

Answers

  • zoya faberov
    zoya faberov ✭✭✭✭✭

    Hello @Piotr Gorazdowski,

    In RDMFieldDictionary LENGTH is the length of the field that should be expected by the consumer ( and published by the publisher), believe this is the length that you are likely interested in as a developer.

    While RWF is the protocol (Refinitiv/Reuters Wire Format),so RWF LENGTH is the length when the field is encoded into message and potentially transferred across Refinitiv Real Time Distribution System ( formerly TREP).

    However, this is a quick, static reference for developers.

    You can learn more of fields and definitions by looking them up via Data Model Discovery tool, as well as which exchanges populate the specific field and with what information they are being populated.

    Next, if you are looking for further details, Refinitiv Helpdesk Online -> Content, is how as a customer you can obtain an authoritative answer to question on specific content, by connecting the customer with a Refinitiv content expert on the specific content set.


  • umer.nalla
    umer.nalla LSEG

    Hi @Piotr Gorazdowski

    The RDMUsageGuide pdf file that is provided with all our Realtime SDKs has some brief information on the above fields e.g.

    image

    The LENGTH column applies to MarketFeed data (SSL type connection)


  • Piotr Gorazdowski
    Piotr Gorazdowski Newcomer
    https://community.developers.refinitiv.com/discussion/comment/75528#Comment_75528

    Hi Umer,


    Yes, I had that doc before but still could not figure out the exact meaning of the RWF length value.

    Looking at the table at 5.5.2.2 FIELD TYPE Keywords

    I suspect values in "LENGTH" column represent actual amount of characters a field can have where as "RWF LEN" shows values mostly with half values of "LENGTH" which I suspect is due to the fields being coded in hexadecimal values for RWF.

    Or Am I mistaken and there is other logic behind the values.

    Thanks

    Piotr


  • zoya faberov
    zoya faberov ✭✭✭✭✭

    Hello @Piotr Gorazdowski,

    To try summarize the previous answers from @umer.nalla and me:

    LENGTH is the maximum length to be populated in the given field, and it is probably of interest to you

    RWF LEN is the length of the field in the encoded message, on the wire, and is likely not of interest to you, unless you need to plan capacity, and estimate the sizes of the encoded messages in this context.

  • Piotr Gorazdowski
    Piotr Gorazdowski Newcomer

    Hi Zoya,

    Well we are creating some custom fields so for example I need to know how to specify exactly the length.

    Does the LENGTH value represent the actual characters or something else.

    For example price 1234567,89 would be length 10 if those would be characters that count as length value.

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