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From Mark <>
Subject Re: MySQLJDBCDataModel vs FileDataModel
Date Mon, 04 Jul 2011 17:13:49 GMT
Ahh ok. So if I want everything in memory like the file backed solution 
I should use ReloadFromJDBCDataModel? I'm going to give that a try right 

Typically which solution is recommended for production use?


On 7/4/11 10:09 AM, Sean Owen wrote:
> Yes, this is trading memory for speed. If you can fit everything in memory,
> then you should. FileDataModel is in memory.
> MySQLJDBCDataModel is not in memory and queries the DB every time. This is
> pretty slow, though by caching item-item similarity as you do, a lot of the
> load is removed. However if you want to go all in memory, use
> ReloadFromJDBCDataModel.
> (The naming is weirder than the actual structure or logic...)
> On Mon, Jul 4, 2011 at 6:05 PM, Mark<>  wrote:
>> I've read the source for FileDataModel and it suggested using a JDBC backed
>> implementation for larger datasets so I decided to upgrade our
>> recommendation system to use MySQLJDBCDataModel with
>> MySQLJDBCInMemoryItemSimilarit**y.
>> I've found that the JDBC backed versions performance is actually worse that
>> FileDataModel and FileItemSimilarity versions. Should this be the case?
>> Which versions are most people using out there? Any recommendations?
>> Thanks

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