Well, I have an index with 5.2 million records (each record containing 3 fields) and it sometimes takes about a minute and a half for results to come back. I have noticed however, that when I run the same query the second time the result comes back faster. I just thought that this was a bit too slow and that perhaps I should implement a caching strategy.
-----Original Message----- From: Erick Erickson [mailto:[EMAIL PROTECTED] Sent: 14 February 2007 14:11 To: java-user@lucene.apache.org Subject: Re: Caching This is really an unanswerable question, since, to steal a phrase, "It depends" <G>... Do you have any reason to believe that the current performance is inadequate for you application? Caching is notoriously difficult to get right, so I wouldn't go there unless there is a *demonstrated* need. By demonstrated, I mean that you run some tests against your actual data with simulated queries and measure. By definition, Lucene's caching is "any good" if your performance meets your target as is. Only if your application does NOT meet your targets should you consider an additional caching layer. And even in this case, I'd spend significant time looking at exactly *where* in my application things were slow rather than jump to caching as an answer. I do not believe that Lucene actually caches the results of queries. I believe that Lucene builds caches of terms, sorting information, etc. that are then applied to all subsequent queries, and that these are the caches that are built at the first query. So, say storing the results of a query somewhere and returning that stored copy for the *next* query that is identical is not something I'd expect Lucene to do. Best Erick On 2/14/07, Kainth, Sachin <[EMAIL PROTECTED]> wrote: > > Hi all, > > I have read that Lucene performs caching of search results so that if > you perform the same search in succession the second result should be > returned faster. What I wanted to ask is whether this caching is any > good or whether it's a good idea to add some sort of caching layer on > top of Lucene to improve on it. > > Any comments will be appreciated. > > Thanks > > Sachin > > > > This email and any attached files are confidential and copyright > protected. If you are not the addressee, any dissemination of this > communication is strictly prohibited. Unless otherwise expressly > agreed in writing, nothing stated in this communication shall be legally binding. > > The ultimate parent company of the Atkins Group is WS Atkins plc. > Registered in England No. 1885586. Registered Office Woodcote Grove, > Ashley Road, Epsom, Surrey KT18 5BW. > > Consider the environment. Please don't print this e-mail unless you > really need to. > This message has been scanned for viruses by MailControl - (see http://bluepages.wsatkins.co.uk/?4318150) --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
