Module mz_transform::notice

Notices that the optimizer wants to show to users.

The top-level notice types are RawOptimizerNotice (for notices emitted by optimizer pipelines) and OptimizerNotice (for notices stored in the catalog memory). The adapter module contains code for converting the former to the latter.

The RawOptimizerNotice type is an enum generated by the raw_optimizer_notices macro. Each notice type lives in its own submodule and implements the OptimizerNoticeApi trait.

To add a new notice do the following:

1. Create a new submodule.
2. Define a struct for the new notice in that submodule.
3. Implement OptimizerNoticeApi for that struct.
4. Re-export the notice type in this module.
5. Add the notice type to the raw_optimizer_notices macro which generates the RawOptimizerNotice enum and other boilerplate code.

Structs

• HumanizedAction
  A wrapper for the OptimizerNoticeApi::fmt_action that implements fmt::Display.
• HumanizedHint
  A wrapper for the OptimizerNoticeApi::fmt_hint that implements fmt::Display.
• HumanizedMessage
  A wrapper for the OptimizerNoticeApi::fmt_message that implements fmt::Display.
• IndexAlreadyExists
  Trying to re-create an index that already exists.
• IndexKeyEmpty
  An index with an empty key is maximally skewed (all of the data goes to a single worker), and is almost never really useful. It’s slightly useful for a cross join, because a cross join also has an empty key, so we avoid rearranging the input. However, this is still not very useful, because
• IndexTooWideForLiteralConstraints
  An index could be used for some literal constraints if the index included only a subset of its columns.
• OptimizerNotice
  An long lived in-memory representation of a RawOptimizerNotice that is meant to be kept as part of the hydrated catalog state.

Enums

• Action
  An action attached to an OptimizerNotice
• ActionKind
• OptimizerNoticeKind
• RawOptimizerNotice
  Notices that the optimizer wants to show to users.

Traits

• OptimizerNoticeApi
  An API structs RawOptimizerNotice wrapped by structs