When statistics refresh

Worked examples, recomputed

Every number the mechanisms quote for this relationship is recomputed from it, so none of them disagrees with it.

• a billion rows → 100,000,050 changes
• at 1% growth a day → ≈ 10 days to refresh

Where it appears

Each mechanism states it in its own names. The general symbol each name stands for is shown with it.

• Query Planning & Optimization

  How does a system choose a plan for a question when the facts that decide the best plan are unknown until the plan has run?

  $$0.1\times n+50$$

  Read it in place →