Hi Mikhail, Thanks a lot for the reply.
You mentioned that q=+{!parent which.. v='+text:hello +person:A'} +{!parent which..v='+text:ciao +person:B'} is the way to go. How would it look like precisely for the following collection? { "id":1, "_childDocuments_": [ {"id":"1_1", "person":"Vai" , "time":"3:14", "msg":"Hello"}, {"id":"1_2", "person":"Arturas" , "time":"3:14", "msg":"Hello"}, {"id":"1_3", "person":"Vai" , "time":"3:15", "msg":"Coz Mathias is working on another system- different screen."}, {"id":"1_4", "person":"Vai" , "time":"3:15", "msg":"It can get annoying"}, {"id":"1_5", "person":"Arturas" , "time":"3:15", "msg":"Thank you. this is very nice of you"}, {"id":"1_6", "person":"Vai" , "time":"3:16", "msg":"ciao"}, {"id":"1_7", "person":"Arturas" , "time":"3:16", "msg":"ciao"} ] }, { "id":2, "_childDocuments_": [ {"id":"2_1", "person":"Vai" , "time":"4:14", "msg":"Hello"}, {"id":"2_2", "person":"Arturas" , "time":"4:14", "msg":"IBM Watson"}, {"id":"2_3", "person":"Vai" , "time":"4:15", "msg":"need to retain content"}, {"id":"2_4", "person":"Vai" , "time":"4:15", "msg":"It can get annoying"}, {"id":"2_5", "person":"Arturas" , "time":"4:15", "msg":"You can make all your meetings more access"}, {"id":"2_6", "person":"Vai" , "time":"4:16", "msg":"Make every meeting a Skype meeting"}, {"id":"2_7", "person":"Arturas" , "time":"4:16", "msg":"ciao"} ] } Cheers, Arturas On Tue, Apr 3, 2018 at 4:33 PM, Mikhail Khludnev <m...@apache.org> wrote: > Hello, Arturas. > > TLDR; Please find inline below. > > On Tue, Apr 3, 2018 at 5:14 PM, Arturas Mazeika <maze...@gmail.com> wrote: > > > Hi Solr Fans, > > > > I am trying to make sense of information retrieval using expressions like > > "some parent", "*only parent*", " *all parent*". I am also trying to > > understand the syntax "!parent which" and "!child of". On the technical > > level, I am reading the following documents: > > > > [1] > > https://lucene.apache.org/solr/guide/7_2/other-parsers. > > html#block-join-query-parsers > > [2] > > https://lucene.apache.org/solr/guide/7_2/uploading-data- > > with-index-handlers.html#nested-child-documents > > [3] http://yonik.com/solr-nested-objects/ > > > > and I am confused to read: > > > > This parser takes a query that matches some parent documents and returns > > their children. The syntax for this parser is: q={!child > > of=<allParents>}<someParents>. The parameter allParents is a filter that > > matches *only parent documents*; here you would define the field and > value > > that you used to identify *all parent documents*. The parameter > someParents > > identifies a query that will match some of the parent documents. The > output > > is the children. > > > > The first sentence talks about "matching" but does not define what that > > means (and why it is only some parents matching?). The second sentence > > introduces a syntax of the parser, but blurs the understanding as "some" > > and "all" of parents are combined into one sentence. My understanding is > > that all documents are retrieve that satisfy a query. The query must > > express some constraints on the parent node and some on the child node. I > > have a feeling that "only parent documents" reads "criteria is formulated > > over the parent part of {parent document}->{child document} of entity. > > My simplified conceptual world of solr looks in the following way: > > > > 1. Every document has an ID. > > 2. Every document may have additional attributes > > 3. Text attributes is what's at stake in solr. Sure we can search for > > products that costs at most X, but this is the added functionality. For > > simplicity I am neglecting those here. > > 4. The user has an information need. She expresses it with (key)words and > > hopes to find matching documents. For simplicity, I am skipping all > issues > > related to the information presentation of the documents > > 5. Analysis chain (and inverse index) are the key technologies solr is > > based upon. Once the chain-processing is applied, mathematical logic > kicks > > in, retrieving the documents (that are a set of processed, normalized, > > enriched tokens) matching the query (processed, normalized and enriched > > tokens). Clearly, the logic function can be a fancy one (at least one of > > query token is in the document set of tokens, etc.), ranking is used to > > sort the results. > > 6. A nested document concept is introduced in solr. It needs to be > uploaded > > into the index structure using a specific handlers [2]. A nested > documents > > is a tree. A root may contain children documents, which may be parents of > > grandchildren documents. > > 7. Querying nested documents is supported in the following manner: > > 7.1 Child documents are return that satisfies {parent > > document}->{document} > > 7.2 Parent documents are return that satisfy {document}->{child > > document} > > > > Would I be very wrong to have this conceptual picture? > > > > From this point, the situation is a bit bury in my head. At the core, I > do > > not really understand what "a document" is anymore (since the complete > json > > or xml, so is a sub-json and sub-xml are documents, every document must > > have an ID, does that meant the the subdocuments must have and ID too, or > > sub-ids are also fine?), how to formulate mathematical expressions over > > documents and what it means that the document satisfies my (key)word > query? > > Can we define a document to be the largest entity of information that > does > > not contain any other nested documents [4]? If this is defined and > > communicated like this already where can I find it? There is a use of the > > clarification, as the concept of the document means different things in > > different contexts (e.g., you can update only the "complete document" in > > the index vs. parent document, etc.). > > > > Is it possible to formulate what's going on using mathematical logic? Can > > one express something like > > > > { give documents d : d is a document, d is parent of document c, d > > satisfies logical criteria C1,....,CN, c satisfies logical criteria > > C1',...,CM'} > > { give documents c : c is a document, d is parent of document c, d > > satisfies logical criteria C1,....,CN, c satisfies logical criteria > > C1',...,CM'} > > > > here the meaning of document is as in definition [4] above. > > > > 1. Is it possible to retrieve all parent documents that have two children > > c1 and c2? Consider a document that is a skype chat, and children are > > individual lines of communication in the chat. I would be looking for the > > (parent) documents that have "hello" said by person A and "ciao" said by > > person B (as two different sub-documents). > > > > q=+{!parent which.. v='+text:hello +person:A'} +{!parent which.. > v='+text:ciao +person:B'} > The query syntax is really tricky and cumbersome. > > > > > > 2. Is it possible to search for documents such that they have a > grandchild > > and the grandchild has the word "hello"? > > > > http://blog-archive.griddynamics.com/2013/12/grandchildren-and-siblings- > with-block.html > > > > > > 3. Is it possible to search for documents that do not have children? > > > q=-{!parent which..}type:child > Beware that mixing parents and childfree products is not supported and > causes pain. as a workaround you need to put empty child placeholder doc. > Sic. Sorry. > > > > Is this the right venue to discuss documentation of solr? > > > > Thanks! > > Arturas > > > > > > -- > Sincerely yours > Mikhail Khludnev >