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shuijian-xu / hive

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Causality？ #115

Open shuijian-xu opened 5 years ago

shuijian-xu commented 5 years ago

It would be sufficient to identify causal changes only and to assume that all unidentified changes are noncausal.

shuijian-xu commented 5 years ago

Some changes, as has been previously indicated, can occur to attributes that have the property of false retrospection but that, due to the fact that they are determinants, have a “knock-on” effect on other attributes that might have the property of true retrospection.

shuijian-xu commented 5 years ago

For instance, in the Wine Club, there is a relationship between the address of a customer and the sales area that contains the address. So it could be said that the address determines the sales area.

shuijian-xu commented 5 years ago

the purpose here is quite different and has more to do with the synchronization of the timing of changes to attribute values, to ensure temporal consistency, than the normalization of relations.

shuijian-xu commented 5 years ago

Without such a facility, the data warehouse may be recording inconsistent information. If a customer's address changes, then the sales area code must be checked and updated, if necessary, at the same time as the address change. Where the data relating to addresses and sales areas is derived from different source systems, the temporal synchronization of these changes may be difficult to implement. If temporal synchronization is not achieved, then any subsequent query involving the history of these attributes may produce inaccurate results.