Hey guys, I created a framework I plan to use for a few projects in-house, using ibatis 3. I enjoy the separation of sql, mapping and domain objects, but I have a pretty complex domain model (first class objects may have any number of attributes, hierarchical if neccessary), so writing sql and taking care of things like sorting and paging gets really hard, and screws up the performance. I tried using apache lucene to take the actual searches off my hands, and it works like a charm. I annotate the domain objects with @Indexable annotations, and pass the mapper name (which is retrieved from the spring context), that can query the objects from the db, and index the properties and attributes of the first class objects accordingly *on the application startup*. This builds an index in memory, and the lucene queries just return the IDs of the matching documents, sorted and filtered, and with convenient things like totalCount for paging implementation. The actual data can then be retrieved by simply querying by the primary keys from the relevant tables. Now, there is the issue of how to synchronize the database state with the lucene index. I see a few ways to implement this: 1. Mark the mapper methods that are supposed to change the state of the database with a marker annotation, and create an aspect that intercepts those calls, and updates the lucene index. This has a nasty side effect, that if someone changes the data in the db directly, index won't know about it until the application is restarted, but technically, I can live with that. 2. Create an aspect, that intercepts certain calls in the Ibatis layer, and depending on the operation at hand (insert, update, delete), updates the lucene index. Beats annotating the methods, and is semi-automatic. Not sure at which layer I should intercept this, though - hence, if there's a definite place to hang this aspect on, I'm all ears. 3. Create database triggers, that would fire the events on insert/update/delete using JMS or any other communication mechanism. This is probably the best way to go (my objects have well defined identities), but requires a lot of coding, and would kill the performance on update-heavy operations (imports and such), as the network roundtrip will be required from app server->db server->[app server->db server]->app server (square brackets representing the call of the lucene index update by the trigger), not to mention the hurdles of setting up JMS producer in postgres environment...
There are probably other ways to implement this - I would be very grateful if you guys could share your insights on this. Thanks in advance, Andrius
