Thanks for replying. Unfortuately the table i need to import from is a view and there is no unique key in there i can use as a primary key. How does this affect my using DIH? does it mea i cannot use DIH?
Thanks. On Sun, Sep 4, 2011 at 8:44 PM, Shawn Heisey <s...@elyograg.org> wrote: > On 9/4/2011 12:16 PM, Kissue Kissue wrote: > >> I was reading about DIH on the this Wiki link : >> http://wiki.apache.org/solr/**DataImportHandler#A_shorter_**data-config<http://wiki.apache.org/solr/DataImportHandler#A_shorter_data-config> >> The following was said about entity primary key: "is *optional* and only >> needed when using delta-imports". Does this mean that the primary key is >> mandatory for delta imports? I am asking because i am going to be >> importing >> from a view with no primary key. >> > > I believe what it means is that you have to specify a field to be the > primary key, and that it must exist in all three queries that you defined - > query, deltaQuery and deltaImportQuery. In my case, query and > deltaImportQuery are identical, and deltaQuery is "SELECT 1 AS did". The > only thing this query does is tell the DIH that there is something to do for > a delta-import, which it then uses deltaImportQuery to do. I keep track of > which documents are new outside of Solr and pass values for the query in via > the dataimport URL. > > As you might surmise, did is the primary key in my dataimport config file. > I couldn't say what would happen if your query results have duplicate > values in the primary key field. In my case, did actually is is the primary > key in the database, but I don't think that's required. I use different > fields for primary key and uniqueKey. This allows us a little extra > flexibility in the index. > > Hopefully you do still have a field that is unique (even if it's not a > primary key) that you can use as the primary key in your config file. It's > a good idea to have such a thing available to serve as the uniqueKey in > schema.xml, for automatic overwrites (delete and reinsert) of documents that > change. > > Thanks, > Shawn > >
