The Column Order of a Multi-Column Index Decides Which Statements It Can Serve
Rests on the index structure and on selectivity, and is the node where index design stops being one column at a time. Real slow statements on a web application filter on a tenant or account plus a time range, which is exactly the case this node decides. It also supplies the ordering behaviour that the keyset-pagination node depends on, since keyset paging is unusable without an index in the right order.
Questions this Concept answers
- Why does an index on (customer_id, created_at) do nothing for a statement that filters only on created_at?
How Database Indexes Speed Up Lookups with B-Tree Hash and LSM Tree Structures
A database index is an auxiliary, ordered (or hashed) data structure built over one or more columns that stores key values together with row identifiers, reducing lookup cost from the O(n) of a full …