On 4/9/15 9:13 AM, Bruno Albuquerque wrote: > I have this index with around 4.5 million documents. When i do some queries > on it, it takes a couple of hundred ms to complete... but only the first > time I do them. If I repeat the same search another time, it answers the > queries an order of magnitude faster. More interestingly, it continues > being faster even after I restart my client code, which leads me to believe > that some optimization happens when I do a query and is persisted into the > index. > > What is the mechanism that is making that happen? Is that just a cache > being written to the index itself or is it something fancier? if it is > something fancier, is there a way to "warm up" the index in a way that most > queries would be faster from the get go (even at the cost of space)? > > Thanks in advance. >
You're experiencing the Lucy "the OS is our JVM"[0] philosophy of mmap[1]. I don't think there's a way to pre-warm it, other than creating and exercising a Searcher. [0] http://lucene.472066.n3.nabble.com/Lucy-Wiki-Update-of-quot-LucyIncubatorProposal-quot-by-MarvinHumphrey-td934939.html [1] http://en.wikipedia.org/wiki/Mmap -- Peter Karman . www.peknet.com . @peterkarman
