5
votes
2answers
130 views

Why is an entire index that is infrequently used stored in the buffer pool?

I have been looking at the memory usage of a server and noticed something odd when drilling into the details. One index is eating up ~15GB of the buffer pool. That happens to be the size of the entire ...
0
votes
1answer
48 views

Query when index is ready

To improve performance of a query I set up an in-memory table and fill it with data. Of course to increase speed I will use an index on the data stored in the in-memory table. create table helper ( ...
7
votes
3answers
5k views

What is the default order of records for a SELECT statement in MySQL?

Suppose you have the following table and data: create table t(k int, v int,index k(k)) engine=memory; insert into t values(10, 1), (10, 2), (10, 3); When issuing select * from t where k = 10 with ...