Abstract: A hybrid-sharded index includes document-sharded posting lists and term-sharded posting lists. Implementations include systems and methods for updating a hybrid-sharded index. For example, a method may include receiving updates to the hybrid-sharded index and generating, at a first leaf node, replacement posting lists and change information for a respective second leaf node. The method may also include 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 and sending the portions to respective leaf nodes. At a particular leaf node of the second leaf nodes, the method includes merging a received portion into an updated posing list portion, swapping the updated posting list portion into memory. During the swap, the change information and the updated posting list portion are used to respond to a query with an older version of the hybrid-sharded index.

Abstract: A hybrid-sharded index includes document-sharded posting lists and term-sharded posting lists. Implementations include systems and methods using a distributed hybrid-sharded index. For example, a method may include receiving, at a root node, a query having a first term and a second term and determining, that the first term is term-sharded. The method may also include retrieving a term-sharded posting list for the first term from a first leaf node that stores the term-sharded posting list and determining, at the root node, a second leaf node that stores a document-sharded posting list for the second term. The method may include sending the second term and a sub-set of documents from the term-sharded posting list to the second leaf node, the sub-set being documents assigned to the second leaf node; and generating a search result using a response received from the second leaf node.

Abstract: Systems and methods are provided for processing a query at a computer system. The method includes building a query tree based on the query and grouping at least some nodes of the query tree into a group of nodes. Grouping is based on an operator node that is a parent of the at least some nodes. The group of nodes retains the functionality of the operator node but the operator node is eliminated by replacing the operator node with the group of nodes in the query tree. The method also includes traversing the query tree to obtain a result list from a search index that is responsive to the query.