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Chapter 16. Conclusion > Enterprise Contextualization

Enterprise Contextualization

As temporal data has become increasingly important, much of it has migrated from being reconstructable temporal data to being queryable temporal data. But much of that queryable temporal data is still isolated in data warehouses or other historical databases, although some of it also exists in production databases as history tables, or as version tables. Often, this queryable temporal data fails to distinguish between data which reflects changes in the real world, and data which corrects mistakes in earlier data.

So business needs for a collection of temporal data against which queries can be written are often difficult to meet. Some of the needed data may be in a data warehouse; the rest of it may be contained in various history tables and version tables in the production database, and the odds of those history tables all using the same schemas and all being updated according to the same rules are not good. As for version tables, we have seen how many different kinds there are, and how difficult it can be to write queries that extract exactly the desired data from them.


  

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