In May 2001 this newsletter took a number of looks at the form and structure of directory storage from traditional x.500-style hierarchical structures (which later were, incorrectly, called "LDAP directories") through to relational database management systems (RDBMS) used to store directory data. There was even a proposal for a hybrid object-oriented relational database (ORDBMS). I had high praise for a white paper (still available here) written by the U.K.'s Nexor Ltd. called "Object-Oriented Databases and Mission-Critical Directories" (sort of ruins the mystery of "which model did they favor?"). It discusses main memory systems, B-Tree file systems, RDBMSs, object-relational DBMSs and pure object DBMSs as data storage facilities for a directory service, then goes on to show the performance differences among the different types and is still relevant.
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But when it comes to hybrid systems, none has stood the test of time like Radiant Logic's RadiantOne server.
I introduced it to my readers back in May 2001 by asking: "Suppose, then, that data was written to an RDBMS with all of the robustness, security and integrity that implies but was read from an object-oriented, hierarchical main-memory style directory information base with all of its performance and ease of use benefits? How's that for the best of both worlds?"
Michel Prompt explained to me the "aha!" moment when he realized that writing to the directory and reading from the directory were very separate functions, performed by very different people and applications so there was no need to keep both the virtual directory server and the physical directory server using the same database design.
What was important, Prompt told me, was structuring communications between the virtual and physical structures on the one hand and between the virtual server and the applications reading it on the other -- and between the physical server and the source of the data it holds, or points to, on the third hand. (When you think "outside the box" you can visualize using three hands!)
Prompt is still innovating in the directory space (as last issue's announcement of Cloud Federation Service for RadiantOne shows) -- and probably still will be 10 years in the future. But what will that future directory look like? Come back next time for a sneak peek.