Create/Update

Create and update are the same operation in Solr (and SolrNet). It's mapped to the Add() method in the ISolrOperations<T> interface.

There are two overloads of Add(): one takes a single document as parameter, the other takes a IEnumerable of documents. Keep in mind that one call to any of these Add() methods will end up in one HTTP request to Solr. So for example this:

ISolrOperations<MyDocument> solr = ...
for (var i = 0; i < 100; i++)
  solr.Add(new MyDocument(i));

is not the same as this:

var documents = Enumerable.Range(0, 100).Select(i => new MyDocument(i));
solr.Add(documents);

If you Add() a document that already exists in the Solr index, it's replaced (using the unique key as equality)

There's also AddWithBoost() (also with single-document and IEnumerable overloads) that you can use to apply an index-time boosting to the added documents.

Add() supports the commitWithin and overwrite parameters. See the Solr wiki for more information about them.

Retrieve

See Querying

Delete

The ISolrOperations<T> interface has several Delete() overloads:

• Delete(T doc): deletes a single document using its unique key to identify it.
• Delete(string id): deletes a single document with a unique key
• Delete(IEnumerable<T> docs): deletes a batch of documents in a single shot.
• Delete(IEnumerable<string> ids): deletes a batch of documents in a single shot.
• Delete(ISolrQuery q): deletes all documents that match a query.
• Delete(IEnumerable<string> ids, ISolrQuery q): deletes a batch of documents and all documents that match a query in a single shot.

Commit and Optimize

After issuing any number of Add() or Delete() operations, be sure to call Commit():

solr.Add(myDocument);
solr.Add(anotherDocument);
solr.Delete(oldDocument);
solr.Commit();

... this tells Solr to finalise the changes you have made and to start rebuilding indexes and related data.

Obviously this has a performance penalty on the Solr instance as all query caches are cleared and repopulated due to the new index.

Alternatively, you can let Solr manage commits, enabling the autoCommit options in the Solr configuration.

The Optimize() method:

solr.Optimize();

... issues a command to tell Solr to begin optimizing its indexes. Again this is an expensive operation in terms of the Solr instance and shouldn't be called too frequently.

Additional information on committing and optmization considerations can be found here

Rollback

(SolrNet 0.4.0)

Rollback() rollbacks all add/deletes made to the index since the last commit. Note that this is nothing like the rollback of relational databases. See the Solr wiki for more information.