MDDL and the Quest for a Market Data Standard

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64 MDDL and the Quest for a Market Data Standard

sent. It also requires additional processing by the receiving application, as it will

need to normalize the information before being able to process it.

Just a final point regarding the use of inheritance: whenever possible, always err

on the side of simplicity rather than reducing message size, just because it’s possible.

It’s far better to reduce bandwidth using data compression techniques, examined later

in this book.

MDDL extensions

One of MDDL’s biggest strengths is its extensibility. This is provided by use of the

other container, which is designed so that firms using MDDL could add terms to

meet their specific requirements and that could, at a later stage, easily be migrated

into the standard when the subsequent release was available. The extension process

is easy to use, and it allows for the inheritance of properties and the use of property

types that are defined within the standard itself – for example, it’s possible to specify

mdDecimal within an extension. Overall, when compared to other standards in the

market, it scores top marks for extensibility.

So, why do you need to extend? Even though MDDL contains a comprehensive

set of terms, there is always the need to add vendor or end-user specific terms; these

are the icing on the cake, the value-add a vendor can offer.

Polymorphism

Polymorphism is the ability to assign a different meaning or usage to something

in different contexts. This technique is used within MDDL, and an example can

be seen in the use of the property, code. It is used to represent the code relating

to an instrument when used within the instrumentIdentifier, or the code of a trad-

ing venue when used within placeOfTrade. It can be also used in the following

containers:



agent



collateralType



componentIdentifier



industryIdentifier



issuerClass



issuerRef