Global indexes are useful in Oracle for performance when indexed columns are different from partitioning key. An “index scan” (well it is named “range scan” in Oracle) using a local index has to navigate through all index partitions in that case. For a global index, it is only one tree to scan and this is more efficient than doing the same for a lot of them.
De : Kanninen Anssi EXT <Anssi.Kanninen@digia.com> Envoyé : mardi 26 janvier 2021 11:09 À : pgsql-admin@lists.postgresql.org Objet : RE: Unique constraint across all partitions?
But why use global indexes? Oracle also has local partitioned indexes which are just like we would like to have in PostgreSQL.
