On Jun 3, 2009, at 13:27, Sanne Grinovero wrote:
I am having a similar need in these days; this should be a very
useful
feature, but I'd like more something I could use with the existing API
like
enableFullTextFilter
( "MyShardsSelectionStrategy" ).setParameter( ... )
a practical example:
enableFullTextFilter( "LanguageFilter" ).setParameter( "IT-it" )
The existing IndexShardingStrategy should be able to be smarter and
have something like
DirectoryProvider<?>[] getDirectoryProvidersForQuery( filters &&
options )
That sounds like an elegant approach but we need a way to make it easy
to declare a filter as dump/shard-sensitive only (ie not force the
user to write some Filter implementation). With this knowledge,
HSearch could ignore the dump filter for the actual Lucene filtering
operation.
So a smart ShardingStrategy could do some selections considering this.
I'm currently using sharding to shard my index on 25 different
languages (using per-language stemmers), so this would
be useful but I'd especially need to be able to "label" my different
DirectoryProviders using String identifiers,
I'd suggest to add a getName() to the DirectoryProvider interface: I
would use that to store countrycodes and
keep a map<String,DirectoryProvider> in my ShardingStrategy, so I can
easily select the right DP when
the LanguageFilter is enabled.
I am not too enthusiastic about that. I guess you can solve that if we
make sure to override toString in DirectoryProviders in a meaningful
way. But really you want a Map<FilterRepresentation, DP> with a smart
equals impl for FilterRepresentation talking care of parameters.
Another usage would be to shard an entity on an Enumerated property:
in this case an appropriate ShardingStrategy
could be provided by Search and auto-configured by reading the
possible enum values: that would be a very easy way
to enable sharding on an entity.
You mean for insertion? You can already do that by passing the enum
value in your document and use
getDirectoryProviderForAddition(Class<?> entity, Serializable id,
String idInString, Document document)
Sanne
2009/6/3 Emmanuel Bernard <emmanuel(a)hibernate.org>:
>
>
> Begin forwarded message:
>
> From: chase.seibert+opensubscriber(a)gmail.com
> Date: June 3, 2009 09:21:21 PDT
> To: emmanuel(a)hibernate.org
> Subject: Re: Re: [hibernate-dev] HSearch: Using sharding and
> avoiding query
> on multiple shards
> Reply-To: chase.seibert+opensubscriber(a)gmail.com
> Emmanuel,
>
> Regarding HSEARCH-251, and
>
http://www.opensubscriber.com/message/hibernate-dev@lists.jboss.org/97703...
>
> Being able to query just a single shard or subset of shards would be
> awesome. I was thinking of a similar API:
>
> IndexShardingStrategy:
> public DirectoryProvider<?>[]
> getDirectoryProviderForShard(int shardNum);
>
> FullTextQuery:
> public void enableShardFilter(int shardNum);
> public void enableShardFilters(int[] shardNums);
>
> FullTextQuery.buildSearcher() would need to be modified to call
> getDirectoryProviderForShard() for each shardNum if shardNums are
> set,
> otherwise it should continue to use
> getDirectoryProvidersForAllShards();
>
> Calling this API from a consumer's stand-point would look like:
> FullTextQuery fullTextQuery =
> fullTextSession.createFullTextQuery(luceneQuery, entityClass);
> fullTextQuery.enableShardFilter(5);
> fullTextQuery.list();
>
> This could be changed to pass named shards easily. I could
> prototype this
> and submit a .patch if you are interested.
>
> -Chase
>
> --
> This message was sent on behalf of chase.seibert+opensubscriber(a)gmail.com
> at
>
openSubscriber.com
>
http://www.opensubscriber.com/message/hibernate-dev@lists.jboss.org/98005...
>
>
> _______________________________________________
> hibernate-dev mailing list
> hibernate-dev(a)lists.jboss.org
>
https://lists.jboss.org/mailman/listinfo/hibernate-dev
>
>