near-real-time

I am using Lucene 6.6.0 and I would like to use the near real-time search feature of Lucene. However, I could not manage to implement it. The way I try to get the feature is as follows: I initialize an IndexReader instance: this.reader = DirectoryReader.open(this.directory); Let's assume some changes have been made in the index via an IndexWriter instance. Then, if I understand correctly, I need a second instance of IndexReader to commit updates: this.newReader = DirectoryReader.openIfChanged(this.reader); if (this.newReader != null) { // Update the IndexSearcher with the new IndexReader

I am having trouble deciding on whether to classify my application as 'real time' or 'near real time', or perhaps even something else. The software receives data immediately as it is generated from the source, then based on certain rules, raises an alert when certain conditions are met. It takes the approach of checking the last 30 seconds of data every 30 seconds to see whether the criteria for a rule has been met. Is that real time? What are the thresholds for the definitions of real time vs. near real-time? EDIT I think this is a duplicate of Define realtime on the web for business . Please

I may be doing an iPhone-based application doing near-real-time sound-processing (filtering, etc). I was wondering the best way to get started. Would I want to create an audio cue for recording and processing sound, as described here ? Edit: I should be clear. I am not asking how to do signal processing, in general. I know some of that and my team's expert will handle the rest. I asking what the "low level" interfaces to sound data on the iphone are. Edit2: My iphone development has been pushed back a week or two so I don't have access to the deve kit right now. Once I have access to the kit,

Background: I have a PostgreSQL (v8.3) database that is heavily optimized for OLTP. I need to extract data from it on a semi real-time basis (some-one is bound to ask what semi real-time means and the answer is as frequently as I reasonably can but I will be pragmatic, as a benchmark lets say we are hoping for every 15min) and feed it into a data-warehouse. How much data? At peak times we are talking approx 80-100k rows per min hitting the OLTP side, off-peak this will drop significantly to 15-20k. The most frequently updated rows are ~64 bytes each but there are various tables etc so the data