Do you find it necessary to customize the quickfix data dictionary?

Question

In the FIX.4.4 data dictionary XML bundled with the quickfix library, it appears that some fields are marked as required that possibly should not be according to protocol specs as described in FIXimate.

For example:

35/OrderId in message AE/TradeCaptureReport's component group TrdCapRptSideGrp 552/NoSides

Another example:

15/ExecType in message AR/TradeCaptureReportAck

I am thinking that these fields should not be required, and that I can simply mark them as required='N' in the FIX44.xml in my data dictionary.

Is it at all surprising that I am finding questionable required='Y' in the stock data dictionary? Should I be at all concerned about changing these?

Casket

Answer 1

It's best to consider the FIX's default data dictionaries as nothing more than a suggestion.

In practice, every counterparty does things a little differently and may use certain fields in different ways. Additionally, most counterparties like to add custom fields to messages (or even all new messages!), and you'll need to adjust your data dictionary XML to match, so that the engine knows what fields to expect.

In practice, I've never seen a counterparty that didn't screw with the data dictionary at least a little. You really have to check each firm's specs; assume nothing.

Thyratron

For counterparties that provide a detailed spec for their messages, is there any advantage to modifying a standard data dict (i.e. FIX 4.2) to match the spec rather than creating a new data dictionary that only includes the fields in the counterparty's spec? I think a custom dict that only includes fields in the spec would be easier to maintain, but I want to make sure I'm not missing anything. – Caller

@Caller Yes, that's a perfectly good approach. I've done that myself. Kinda depends on your situation. It's much easier to maintain a dictionary that's cut down to only what you need, but it's not always worth your time to bother. A couple times I've started with some tweaks to the original, and then later on when the dust has settled I take a machete to it. – Thyratron