darkpools are non-exchange, non-published exchange which doesn’t have the same reporting obligations of a stock market. The only thing they have to report is the actual filled transactions after 90 seconds.

darkpools are used because the order book/bid-ask spread is not leaked, which means large transactions will not be able to influence the market as much.

For data inference tasks, categorical data

Given \(\geq 2\) points, we can then start creating interpolations for missing data.

See polynomial interpolation

nearest neighbor method and data interpolation

you can think of nearest neighbor method as piecewise-constant interpolation

MAGIC

initialize a symmetric, positive definite matrix \(Q\). Then, run the update expressions given in the book.

optimize for a Secant Method equation which satisfies the Curvature Condition.

Database Page

each Database Page is given a unique identifier; a page ID could be unique per DBMS, per DB, or per table—page IDs is indirection to physical location.

• a Database Page is a fixed-size block of data
  • tuples
  • meta-data
  • indicies
  • log records
  • …
• most systems do not mix page types (don’t mix different tables, do not mix different types, etc.)
• some systems require a page to be self contained (no pointers, etc.) — for fault tolerance

Whoops, we accidentally overloaded a word

• Hardware Page (4kb, i.e. a block on the physical disk)
• OS Page (usually a block, notionally different for now but abstracted, 2mb, 1gb)
• Database Page

each Database Page is automatically read/written