Update and delete

Delete by query

IndexWriter.DeleteDocuments accepts a TermQuery. Use it to remove documents matching an identifier:

writer.DeleteDocuments(new TermQuery("id", "abc-123"));
writer.Commit();

Deletes are buffered and applied at commit time. Until commit, the deletes are not visible to new searchers.

Update

UpdateDocument is delete-then-add by an identifier term:

var doc = new LeanDocument();
doc.Add(new StringField("id", "abc-123"));
doc.Add(new TextField("body", "Updated content"));

writer.UpdateDocument(new TermQuery("id", "abc-123"), doc);
writer.Commit();

The delete and add land in the same commit, so readers never see a window where the document is missing.

Tombstones

Deletes are written as a per-segment .del bitset. They are merged out when the segment is rewritten by a background merge.

See also

• DeleteDocuments
• UpdateDocument