17. Ancient Data Warehousing

Although it only now has become a common term as the core of business intelligence, the practice of data warehousing has been with us for over five-hundred years. Since the early Italian renaissance, merchants have kept databases of their business transactions wherein each transaction was related to the critical dimensions that characterized its type and the effect that it had on the business.

More specifically, each transaction, representing a transfer of financial resources from one place to another, was related to the source and destination of the transfer. Each transactions was related to the place from which it was withdrawn and the place to which it was deposited in what has come to be known as double-entry bookkeeping. The record of the withdrawal was referred to as the “credit” entry and the record of the deposit was referred to as the “debit” entry.

Like all data warehouses, each of transactions was also related to the date of its occurrence, allowing the merchant to sort and sum the transactions to measure the activity of the business during given periods of time. Furthermore, the financial state of a business could be determined by summing the deposits to a given account, then summing the withdrawals from the same, and finding the account’s “balance,” or state, by subtracting the withdrawals from the deposits.

This process of relating transactions to its critical factors (“dimensions”) and summing the transactions according to these critical factors is exactly how a modern data warehouse is used. The data warehouse, the central focus of the field of business intelligence, is universally implemented as a multidimensional database. The multidimensional database, like the bookkeeper’s journal, is made up of chronologically ordered records that represent business transactions with each transaction related to the customers, products, accounts, dates, and other “dimensions” of its existence. The data warehouse is, in effect, a journal of business transactions in the same way that the accountant’s book of original entry (his “journal”) is.

So, what is the difference between a traditional bookkeeping journal and a modern data warehouse? Only the existence of the SQL language (or some equivalent database query language). The modern query language, allows the user to sum and sort transactions by any combination of its many dimensions, including the transactions date and its debit and credit accounts.

Because the renaissance bookkeeper did not have modern database automation, he needed to first sort the transactions into individual databases (called “ledger accounts”) and then sort them again into rigid time frames (called “reporting periods”). Because of these once necessary and arduous sorting tasks, the business intelligence of times past was slow, expensive, error-prone, and untimely. And because we have not integrated financial reporting and analysis into common business intelligence practices, financial information has continued to be untimely to this day.