Checkpoint 1 - NBA_TEST_1

Checkpoint 1 - NBA_TEST_3

Checkpoint 1 - NBA_TEST_6

Checkpoint 1 - NBA_TEST_7

Opportunity: Views exist to be queried frequently

Idea: Pre-compute and save the view’s contents!
(like an index)

When the base data changes,
the view needs to be updated too!

Our view starts off initialized

Idea: Recompute the view from scratch when data changes.

Not quite facepalm-worthy, but not ideal.

Intuition

What is $\Delta \mathcal R$?

A Set/Bag of Insertions

+

A Set/Bag of Deletions

$\sigma(\mathcal R) \rightarrow \sigma(\mathcal R \uplus \Delta \mathcal R)$

$\equiv$ $\sigma(\mathcal R)$ $\uplus$ $\sigma(\Delta \mathcal R)$

Set/Bag difference also commutes through selection

$\pi(\mathcal R) \rightarrow \pi(\mathcal R \uplus \Delta \mathcal R)$

$\equiv$ $\pi(\mathcal R)$ $\uplus$ $\pi(\Delta \mathcal R)$

Does this work under set semantics?

$\mathcal R_1 \uplus \mathcal R_2 \rightarrow \mathcal R_1 \uplus \Delta \mathcal R_1 \uplus \mathcal R_2 \uplus \Delta \mathcal R_2$

$\equiv$ $\mathcal R_1 \uplus \mathcal R_2$ $\uplus$ $\Delta \mathcal R_1 \uplus \Delta \mathcal R_2$

How do we derive $\Delta Q$?

So far: $$\Delta Q_{ins}(\mathcal D, \Delta \mathcal D) = Q(\Delta \mathcal Q_{ins})$$ $$\Delta Q_{del}(\mathcal D, \Delta \mathcal D) = Q(\Delta \mathcal Q_{del})$$