OSPF Incremental SPF and receipt of LSAs
Incremental SPF is an improvement in the efficiency of OSPF such that only the portions of the Shortest Path Tree (SPT) that have changed are included in the execution of the algorithm. Under normal circumstances, when an OSPF router receives an LSA of any type that is new, it will run the SPF algorithm in full.
Whether a full SPF or an incremental SPF is run It does not depend on whether a single LSA or the whole LSDB is exchanged. It has to do with the the way in which the received updates are processed.
For further information about the different LSA types, take a look at:
Links
https://networklessons.com/cisco/ccie-routing-switching-written/ospf-incremental-spf https://networklessons.com/ospf/ospf-lsa-types-explained https://networklessons.com/ospf/ospf-lsas-and-lsdb-flooding-tutorial