This paper proposes a new page layout which improves cache efficiency.
The classic "slotted page" layout is shown above. It is great for accessing data record-by-record, but it exhibits poor cache usage during predicate evaluation because it brings other unused data into the cache line.
Compare this to PAX, where subsequent data are passively "prefetched" as it is brought together into the cache. This lead to better cache efficiency. However, PAX needs to reconstruct tuples, although this cost is minimal (no changes in IO).
PAX contains the same set of tuples as classic "slotted page", so it exhibits the same IO patterns. It only reorders the inner page layout.
Question:
- It makes sense for this layout to be used in OLAP workloads (columnar storage). But why is this page layout not used by all OLTP databases as well?
This paper proposes a new page layout which improves cache efficiency.
The classic "slotted page" layout is shown above. It is great for accessing data record-by-record, but it exhibits poor cache usage during predicate evaluation because it brings other unused data into the cache line.
Compare this to PAX, where subsequent data are passively "prefetched" as it is brought together into the cache. This lead to better cache efficiency. However, PAX needs to reconstruct tuples, although this cost is minimal (no changes in IO).
PAX contains the same set of tuples as classic "slotted page", so it exhibits the same IO patterns. It only reorders the inner page layout.
Question: