: I.E. Instruct Solr that you are interested in documents that match a : given query and then have Solr notify you (through whatever callback : mechanism is specified) if and when a document appears that matches the : query. : : We are planning on writing some software that will effectively grind : Solr to give us the same behaviour, but if Solr has this registration : built in, it would be very useful and much easier on our resources...
it does not, but there are typically two ways people deal with this depending on the balance of your variables... * max latency of notificications after doc is added/updated * rate of churn of documents in index * number of registered queries for notification 1) if you have a heavy churn of documents, and the max latency allowed for notification is large, then doing periodic polling at a frequency of that latency can be preferably to minimize the amount of redundent work 2) if the churn on documents is going to be relatively small and/or the number of registered queries is going to be relatively large, you can invert the problem and build an index where each document represents a query, and as documents are added/updated you use the terms in those documents to query your "query index" (this could even be done as an UpdateProcessor on your doc core, querying over to some other "notifications" core) (disclaimer: i've never implemented any of these ideas personally, this is just what i've picked up over the years on hte mailing lists) -Hoss
