[hibernate-issues] [Hibernate-JIRA] Commented: (HSEARCH-135) Create a RAMDirectoryProvider from an existing Lucene FSDirectory

[ http://opensource.atlassian.com/projects/hibernate/browse/HSEARCH-135?pag... ] Hardy Ferentschik commented on HSEARCH-135: ------------------------------------------- [11:00am] hardy_: I was wondering whether you have some more experience now with RamDirectory vd FSDirectory in Lucene [11:00am] hardy_: https://forum.hibernate.org/viewtopic.php?f=9&t=1000523 [11:01am] hardy_: http://opensource.atlassian.com/projects/hibernate/browse/HSEARCH-135 [11:01am] hardy_: I created HSEARCH-135 a while ago, because I also thought it would be a good idea to use a RAMDirectory, but initalise it with a FSDirectory [11:02am] sannegrinovero: ah yer I remember that [11:02am] sannegrinovero: like more than a year ago [11:02am] hardy_: I am not sure if this actually still makes snese [11:03am] sannegrinovero: my point is that RAMDirectory isn't faster than FSDirectory, when testing on non-trivial indexes [11:04am] hardy_: right. I think that was also Emmanuel's take on it [11:04am] sannegrinovero: but if you think the feature ads value, it's easy to implement, so no reason to not making it, besides dev time. [11:04am] hardy_: i see [11:04am] hardy_: I think the guy on the forum might have a point with the configuration [11:05am] sannegrinovero: the NIODirectory is also interesting, but is in high complexity [11:05am] hardy_: I wam wondering whether we should use the RAMDirectory constructor passing the file based index in case indexBase is specified [11:06am] sannegrinovero: "the index is allowed to take xyzMB in the VM and the rest you have to go to disk for." is really an Operating System problem [11:07am] hardy_: right [11:07am] sannegrinovero: that's what you get when using FSDirectory.. OS will use caches as it sees more fit [11:07am] sannegrinovero: that's why FSDirectory is as fast as memory, because it uses memory in clever ways.. on unix at least [11:09am] hardy_: ok, thanks [11:09am] sannegrinovero: so I see he's asking for a clever implementation combining FS+RAM approaches, I think the answer is FSDirectory, RAMDir being more like a toy. [11:10am] sannegrinovero: The feature you opened might be useful in case you want the index to be initialized at startup, but then loose changes and "reset state" at application startup. [11:11am] hardy_: makes sense -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://opensource.atlassian.com/projects/hibernate/secure/Administrators.... - For more information on JIRA, see: http://www.atlassian.com/software/jira