Abstract: Example implementations relate to optimized queries based on unique attributes. For example, a computing device may include a processor. The processor may receive a query and identify at least one unique attribute based on at least one operation specified in the query or based on an attribute property associated with at least one relational table relevant to the query, the attribute property indicating uniqueness. The processor may modify a data structure representing the query, the data structure having nodes each associated with a respective relational table and the data structure modified to specify a subset of the nodes that are associated with the at least one unique attribute. The processor may optimize the query based on the data structure modified to specify the subset.

Abstract: A method for managing database nodes includes determining that a data segment is on a failed node. The data segment is referenced by an operation of a query plan. The method includes selecting a victim node based on a segmentation ring, a buddy node for the data segment, a plurality of remaining operational nodes, and a predetermined selection parameter. The method includes generating a query plan such that the victim node performs double duty for operations accessing the data segment from a buddy projection on the victim node, and operations accessing a data segment for a primary projection of the victim node.

Abstract: Example implementations relate to optimized queries based on unique attributes. For example, a computing device may include a processor. The processor may receive a query and identify at least one unique attribute based on at least one operation specified in the query or based on an attribute property associated with at least one relational table relevant to the query, the attribute property indicating uniqueness. The processor may modify a data structure representing the query, the data structure having nodes each associated with a respective relational table and the data structure modified to specify a subset of the nodes that are associated with the at least one unique attribute. The processor may optimize the query based on the data structure modified to specify the subset.

Abstract: A method for managing database nodes includes determining that a data segment is on a failed node. The data segment is referenced by an operation of a query plan. The method includes selecting a victim node based on a segmentation ring, a buddy node for the data segment, a plurality of remaining operational nodes, and a predetermined selection parameter. The method includes generating a query plan such that the victim node performs double duty for operations accessing the data segment from a buddy projection on the victim node, and operations accessing a data segment for a primary projection of the victim node.