to be closed means that the operation of a group applied to an element of a group would produce another element of the group.

Exploring CLRS.

2

• insertion sort

Disk based architecture

• the DBMS primarily stores stuff on non-violatle disk
• meaning: the DBMS’ job is to move stuff between violatle and non-volatle storage

Challenges

• how do you makue sure memory-writtten info is commited to disk?

Hierarchy model

there’s a tradeoff because as your system because faster, you have less of it and (in case its volatle) it stays around less long

Access Order

Key challenge: random-access on non-volatile storage is almost always slower than sequential access