>If I understand your suggestion correctly, you said that there's NO need to have many Dynamic Fields; instead, we can have one definitive field name, which can store a long string (concatenation of >information about tens of pictures), e.g., using "-" and "%" delimiters: pic_url_value1-pic_caption_value1-pic_description_value1%pic_url_value2-pic_caption_value2-pic_description_value2%... >I don't clearly see the reason of doing this. Is there a gain in terms of performance? Or does this make programming on the client-side easier? Or something else?
I think you should ask the exact opposite question. If you don't do anything with these fields which Solr is particularly good at (searching / filtering / faceting/ sorting) why go through the trouble of creating dynamic fields? (more fields is more overhead cost/ tracking cost no matter how you look at it) Moreover, indeed from a client-view it's easier the way I suggested, since otherwise you: - would have to ask (through SolrJ) to include all dynamic fields to be returned in the Fl-field ( http://wiki.apache.org/solr/CommonQueryParameters#fl). This is difficult, because a-priori you don't know how many dynamic-fields to query. So in other words you can't just ask SOlr (though SolrJ lik you asked) to just return all dynamic fields beginning with pic_*. (afaik) - your client iterate code (looping the pics) is a bit more involved. HTH, Cheers, Geert-Jan 2010/6/26 Saïd Radhouani <r.steve....@gmail.com> > Thanks Geert-Jan for the detailed answer. Actually, I don't search at all > on these fields. I'm only filtering (w/ vs w/ pic) and sorting (based on the > number of pictures). Thus, your suggestion of adding an extra field NrOfPics > [0,N] would be the best solution. > > Regarding the other suggestion: > > > If you dont need search at all on these fields, the best thing imo is to > > store all pic-related info of all pics together by concatenating them > with > > some delimiter which you know how to seperate at the client-side. > > That or just store it in an external RDB since solr is just sitting on > the > > data and not doing anything intelligent with it. > > If I understand your suggestion correctly, you said that there's NO need to > have many Dynamic Fields; instead, we can have one definitive field name, > which can store a long string (concatenation of information about tens of > pictures), e.g., using "-" and "%" delimiters: > pic_url_value1-pic_caption_value1-pic_description_value1%pic_url_value2-pic_caption_value2-pic_description_value2%... > > I don't clearly see the reason of doing this. Is there a gain in terms of > performance? Or does this make programming on the client-side easier? Or > something else? > > > My other question was: in case we use Dynamic Fields, is there a > documentation about using SolrJ for this purpose? > > Thanks > -Saïd > > On Jun 26, 2010, at 12:29 PM, Geert-Jan Brits wrote: > > > You can treat dynamic fields like any other field, so you can facet, > sort, > > filter, etc on these fields (afaik) > > > > I believe the confusion arises that sometimes the usecase for dynamic > fields > > seems to be ill-understood, i.e: to be able to use them to do some kind > of > > wildcard search, e.g: search for a value in any of the dynamic fields at > > once like pic_url_*. This however is NOT possible. > > > > As far as your question goes: > > > >> Now, I'm trying to make facets on pictures: display doc w/ pic vs. doc > w/o > > pic > >> To the best of my knowledge, everyone is saying that faceting cannot be > > done on dynamic fields (only on definitive field names). Thus, I tried > the > > following and it's working: I assume that the stored > >pictures have a > > sequential number (_1, _2, etc.), i.e., if pic_url_1 exists in the index, > it > > means that the underlying doc has at least one picture: > >> ...&facet=on&facet.field=pic_url_1&facet.mincount=1&fq=pic_url_1:* > >> While this is working fine, I'm wondering whether there's a cleaner way > to > > do the same thing without assuming that pictures have a sequential > number. > > > > If I understand your question correctly: faceting on docs with and > without > > pics could ofcourse by done like you mention, however it would be more > > efficient to have an extra field defined: hasAtLestOnePic with values (0 > | > > 1) > > use that to facet / filter on. > > > > you can extend this to NrOfPics [0,N) if you need to filter / facet on > docs > > with a certain nr of pics. > > > > also I wondered what else you wanted to do with this pic-related info. Do > > you want to search on pic-description / pic-caption for instance? In that > > case the dynamic-fields approach may not be what you want: how would you > > know in which dynamic-field to search for a particular term? Would if be > > pic_desc_1 , or pic_desc_x? Of couse you could OR over all dynamic > fields, > > but you need to know how many pics an upperbound for the nr of pics and > it > > really doesn't feel right, to me at least. > > > > If you need search on pic_description for instance, but don't mind what > pic > > matches, you could create a single field pic_description and put in the > > concat of all pic-descriptions and search on that, or just make it a a > > multi-valued field. > > > > If you dont need search at all on these fields, the best thing imo is to > > store all pic-related info of all pics together by concatenating them > with > > some delimiter which you know how to seperate at the client-side. > > That or just store it in an external RDB since solr is just sitting on > the > > data and not doing anything intelligent with it. > > > > I assume btw that you don't want to sort/ facet on pic-desc / > pic_caption/ > > pic_url either ( I have a hard time thinking of a useful usecase for > that) > > > > HTH, > > > > Geert-Jan > > > > > > > > 2010/6/26 Saïd Radhouani <r.steve....@gmail.com> > > > >> Thanks so much Otis. This is working great. > >> > >> Now, I'm trying to make facets on pictures: display doc w/ pic vs. doc > w/o > >> pic > >> > >> To the best of my knowledge, everyone is saying that faceting cannot be > >> done on dynamic fields (only on definitive field names). Thus, I tried > the > >> following and it's working: I assume that the stored pictures have a > >> sequential number (_1, _2, etc.), i.e., if pic_url_1 exists in the > index, it > >> means that the underlying doc has at least one picture: > >> > >> ...&facet=on&facet.field=pic_url_1&facet.mincount=1&fq=pic_url_1:* > >> > >> While this is working fine, I'm wondering whether there's a cleaner way > to > >> do the same thing without assuming that pictures have a sequential > number. > >> > >> Also, do you have any documentation about handling Dynamic Fields using > >> SolrJ. So far, I found only issues about that on JIRA, but no > documentation. > >> > >> Thanks a lot. > >> > >> -Saïd > >> > >> On Jun 26, 2010, at 1:18 AM, Otis Gospodnetic wrote: > >> > >>> Saïd, > >>> > >>> Dynamic fields could help here, for example imagine a doc with: > >>> id > >>> pic_url_* > >>> pic_caption_* > >>> pic_description_* > >>> > >>> See http://wiki.apache.org/solr/SchemaXml#Dynamic_fields > >>> > >>> So, for you: > >>> > >>> <dynamicField name="pic_url_*" type="string" indexed="true" > >> stored="true"/> > >>> <dynamicField name="pic_caption_*" type="text" indexed="true" > >> stored="true"/> > >>> <dynamicField name="pic_description_*" type="text" indexed="true" > >> stored="true"/> > >>> > >>> Then you can add docs with unlimited number of > >> pic_(url|caption|description)_* fields, e.g. > >>> > >>> id > >>> pic_url_1 > >>> pic_caption_1 > >>> pic_description_1 > >>> > >>> id > >>> pic_url_2 > >>> pic_caption_2 > >>> pic_description_2 > >>> > >>> > >>> Otis > >>> ---- > >>> Sematext :: http://sematext.com/ :: Solr - Lucene - Nutch > >>> Lucene ecosystem search :: http://search-lucene.com/ > >>> > >>> > >>> > >>> ----- Original Message ---- > >>>> From: Saïd Radhouani <r.steve....@gmail.com> > >>>> To: solr-user@lucene.apache.org > >>>> Sent: Fri, June 25, 2010 6:01:13 PM > >>>> Subject: Setting many properties for a multivalued field. Schema.xml ? > >> External file? > >>>> > >>>> Hi, > >>> > >>> I'm trying to index data containing a multivalued field "picture", > >>>> that has three properties: url, caption and description: > >>> > >>> <picture/> > >>>> > >>> <url/> > >>> > >>>> <caption/> > >>> <description/> > >>> > >>> Thus, each > >>>> indexed document might have many pictures, each of them has a url, a > >> caption, > >>>> and a description. > >>> > >>> I wonder wether it's possible to store this data using > >>>> only schema.xml. I couldn't figure it out so far. Instead, I'm > thinking > >> of using > >>>> an external file to sore the properties of each picture, but I haven't > >> tried yet > >>>> this solution, waiting for your suggestions... > >>> > >>> Thanks, > >>> -Saïd > >> > >> > >
