7. The method of claim 1 , wherein the dividing comprises: determining whether a document in the update is in a first set of documents or in a second set of documents; when the document is in the first set, generating the replacement posting list as a document-sharded posting list, wherein the replacement posting list is an updated posting list; and when the document is in the second set, generating the replacement posting list as a term-sharded posting list and performing the dividing, sending, and merging.
1. A method comprising: receiving, using at least one processor of a first leaf node in a distributed environment, updates to a hybrid-sharded index, the hybrid-sharded index including document-sharded posting lists and term-sharded posting lists; generating, using the at least one processor of the first leaf node that received an update, replacement posting lists and change information for a respective second leaf node; dividing the replacement posting lists into portions, a portion having associated change information and being associated with a respective one of the second leaf nodes; sending the portions to respective second leaf nodes; and at a particular leaf node of the second leaf nodes: merging, using at least one processor of the particular leaf node, a received portion into an updated posting list portion, swapping the updated posting list portion into memory, and during the swap, using the change information and the updated posting list portion to respond to a query with an older version of the hybrid-sharded index.