Hi Steve,
Thank you very much for your inputs. Yes, I do know the aliasing mechanism
offered in Solr. I think the whole question boils down to one thing: how
much do you know about the data being stored -- and sometimes you know
nothing about that.
In some cases, you have to provide a generic solution for users to store
and query their own data. With Solr / Lucene backing your storage, you can
easily expose a restricted (but still powerful) subset of the Solr / Lucene
query syntax for querying user-defined data. Things however would start
getting complicated if you have to tell your customers, that the field you
loaded as "foo" must be referred as "foo_s" and the field you loaded "bar"
must be referred as "bar_i", since it contains a number and so on...
Implementing the mapping in your application would be overly complex, as
you would have to maintain a mapping between the internal representation
("foo_s") and the query interface ("foo") and alias results from the
internal format to the format visible to the user ("foo_s" --> "foo"). I
think you get the idea.
I like the way Solr can use the name for specifying type: having a
configuration option (either global or at collection level), which tells
Solr to handle type postfixes slightly differently and strip the type
prefix automatically would be perfectly enough for this use-case.
Imagine the following approach: if configured so, Solr would still create
the field based on the type postfix, but would strip it from the name: for
example, if a document is inserted with the field "foo_s" and "bar_i", Solr
could create a string field named "foo" and a numeric field "bar".
I think this solution would be both backwards compatible (has to be
explicitly enabled) and relatively simple to implement in the Solr code
base. I have created a Jira issue for the feature request:
https://issues.apache.org/jira/browse/SOLR-9150
What do you think?
Thanks,
Peter
2016-05-19 15:30 GMT+02:00 Steve Rowe <sar...@gmail.com>:
> Peter,
>
> It’s an interesting idea. Could you make a Solr JIRA?
>
> I don’t know where the field type specification would go, but providing a
> mechanism to specify field type for previously non-existent fields, outside
> of the field names themselves, seems useful.
>
> In the meantime, do you know about field aliasing?
>
> 1. You can get results back that rename fields to whatever you want: see
> the section “Field Name Aliases” here: <
> https://cwiki.apache.org/confluence/display/solr/Common+Query+Parameters>.
>
> 2. On the query side, eDisMax can perform aliasing so that user-specified
> field names in queries get mapped to one or more indexed fields: look for
> “alias” in <
> https://cwiki.apache.org/confluence/display/solr/The+Extended+DisMax+Query+Parser
> >.
>
> --
> Steve
> www.lucidworks.com
>
> > On May 19, 2016, at 4:43 AM, Horváth Péter Gergely <
> peter.gergely.horv...@gmail.com> wrote:
> >
> > Hi Steve,
> >
> > Yes, I know the schema API, however I do not want to specify the field
> type
> > problematically for every single field.
> >
> > I would like to be able to specify the field type when it is being added
> > (similar to the name postfixes, but without affecting the field names).
> >
> > Thanks,
> > Peter
> >
> >
> > 2016-05-17 17:08 GMT+02:00 Steve Rowe <sar...@gmail.com>:
> >
> >> Hi Peter,
> >>
> >> Are you familiar with the Schema API?: <
> >> https://cwiki.apache.org/confluence/display/solr/Schema+API>
> >>
> >> You can use it to create fields, field types, etc. prior to ingesting
> your
> >> data.
> >>
> >> --
> >> Steve
> >> www.lucidworks.com
> >>
> >>> On May 17, 2016, at 11:05 AM, Horváth Péter Gergely <
> >> peter.gergely.horv...@gmail.com> wrote:
> >>>
> >>> Hi All,
> >>>
> >>> By default Solr allows you to define the type of a dynamic field by
> >>> appending a post-fix to the name itself. E.g. creating a color_s field
> >>> instructs Solr to create a string field. My understanding is that if we
> >> do
> >>> this, all queries must refer the post-fixed field name as well. So
> >>> instead of a query like color:"red", we will have to write something
> like
> >>> color_s:"red" -- and so on for other field types as well.
> >>>
> >>> I am wondering if it is possible to specify the data type used for a
> >> field
> >>> in Solr 6.0.0, without having to modify the field name. (Or at least
> in a
> >>> way that would allow us to use the original field name) Do you have any
> >>> idea, how to achieve this? I am fine, if we have to specify the field
> >> type
> >>> during the insertion of a document, however, I do not want to keep
> using
> >>> post-fixes while running queries...
> >>>
> >>> Thanks,
> >>> Peter
> >>
> >>
>
>
