Total Recall: How the E-Memory Revolution Will Change Everything by C. Gordon Bell, Jim Gemmell

again, I’d have to hunt for it in various folders, asking myself: If I were me, where would I file it right now?
    Librarians have been familiar with this restriction for centuries. A copy of a book can only be on one shelf in just one section, often determined by the Dewey decimal system of book topics. So they created paper card catalogs, where a card was a surrogate for a book. Now the book—or at least its surrogate card—could be filed in more than one place. Dewey might have it placed in the physics section, but it could also be in the title card catalog, filed alphabetically by its title, as well as being filed alphabetically by author in the author card catalog. For your convenience, the Dewey subject index would be duplicated in the card catalog also, allowing you to flip through cards with your fingers rather than hiking down the aisles.
    So here I was, with a system that was worse than a library with paper card catalogs. I was like a librarian who was not allowed to have a card catalog. Jim Gray, who is widely celebrated as a pioneer, even a founding father, of database design, shook his head over me.
    “You need to use a database, Gordon. When are you going to listen to me?” he would ask.
    I was resistant. “We don’t need no stinkin’ databases,” I’d reply.
    My resistance stemmed from my first experiences with databases back in the 1970s. Back then databases were still new and much hyped—they were also space-hogging and hard to use. I knew they’d been improved in the time since, but I’d heard enough horror stories over the years to keep my prejudices well nourished. Also, I wasn’t clear on exactly what I wanted out of even a well-behaved one. But, it turned out Jim Gray was right—as usual.
    A database is a program for storing and retrieving large collections of interrelated information. Modern databases let you very quickly retrieve all the records with a given attribute. You can rapidly sort, sift, and combine information in just about any way you can imagine. There was once a slight technical distinction to be made between how a database could index and look up records and full-text retrieval of documents, but by now databases have subsumed full-text search; they are happy to store documents and perform Google-like retrieval.
    In his memex paper, Bush had expressed hope that the search algorithms of the future would be better than simple index-lookup on some attribute like author or date. He held up the human brain’s associative memory as the ideal. In an associative network, items are linked together by contingency in time and space, by similarity, by context, and by usefulness. There are often numerous paths to each item.
    Bush was right that trails and associative linking were critical components of an effective e-memory machine. But his dismissal of indexing was one of his rare failures of imagination. In his day, indexing meant alphabetical lookup in a predefined, noncompre hensive list of topics or keywords, as in a library card catalog. With the speed of modern computers, it has become possible to index every single word and phrase in every document and to search all of them in an instant. When indices are so comprehensive, and lookup by the index instantaneous, then indexing is actually the mechanism by which associative memory becomes possible.
    The MyLifeBits research project revealed that any system that aspires to be sold as an e-memory machine in the age of Total Recall will have to use a database storage engine, including full-text indexing. Only a database will allow you to create two-way links between items (including annotations) and to regroup and recat egorize items and collections of items in an open-ended fashion. Only full-text indexing will give you keyword access to all of your e-memory.
    With MyLifeBits we could find all items that share a certain property, such as having the same creation date, or having been edited during a particular meeting, or having been