What exactly is "pinning" in relation to indexes in DBMS?
c#, database, mysql, oracle, sql
Solution
When a table or index is pinned, it means it is kept in memory.
The database has a certain amount of memory allocated to work with. Typically, the database caches recently used data.
When an index is pinned, it means the index is kept in memory permanently, rather than being aged out of the cache.
Problem
As part of a test question, students were asked to define and describe pinning in relation to indexes. When one talks about "pinning" in indexes, what exactly is this? Is there some other word/term I can search for, as google has not provided any solutions.