Tuesday, 4 September 2012

The dating game

There's no avoiding it. They can be a source of immense frustration. I am referring, of course, to computer dates - and not the romantic type!! When it is all going well, you hardly know they are there. But beware. Dates are tricky.

Many systems and databases can have their own way of working out dates. They can store them in a bewildering array of formats. The date could also be stored as an integer, and merely converted to a date format by the application, so that when moving from one database to another, you have to factor in an algorithm to compensate.

Dates can be packed into small spaces. They can even be stored as hexadecimal. Many formats are simply not recognised by data quality software, and you may have to resort to flamboyant coding to resolve.

When scheduled systems fail and have to be run late, this can affect system generated dates. When systems become out of synchronisation, very often the data is recovered, but the dates have been delayed, which can have an adverse impact on the phasing of business intelligence reporting. You can often discover the date schedule in one system is permanently out of synchronisation with the other, creating systemic latency.

Perhaps more frustrating about dates is their very definition, especially when trying to share data between disparate systems. Nomenclature is key. But even using consistent naming conventions can cause issues. For instance "Start Date" may have a totally different definition from one system to another.

Also, when you look at a date within a system, are you sure it is correct? A profile may discover lots of dates coinciding with the date that the database started. These are often just put in as default dates when data was migrated over to the new system.

So whatever you do, wherever you are in data services. Do not neglect your dates. Even if you think you have everything planned, think again and again. 

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