Struct Context 

pub struct Context { /* private fields */ }

What the passes are given besides the plan.

Only the settings today. The catalog, the statistics and the planning deadline are the other three things spec/engine/11-optimizer.md puts in here, and each arrives with the first pass that reads it: the statistics with cardinality estimation, the deadline with join ordering, which is the only search in the plan and so the only thing that can spend real time. A field that no pass reads is a field whose meaning nobody has had to decide yet, and deciding it early is how it ends up wrong.

Implementations

impl Context

pub fn new() -> Self

Every pass enabled, which is what a query gets unless it says otherwise.

pub fn without(names: &str) -> Result<Self>

Turns off the passes named in DuckDB’s comma separated spelling.

Empty entries are skipped, so a trailing comma is not an error, which is what the binary does with one.

Errors

For a name that is not a pass, with the sentence the binary prints for one. rudb lists every name it has rather than the closest one by edit distance, which is the same divergence it already has on every other complaint about a name it does not know.

pub fn disable(&mut self, name: &str) -> Result<()>

Turns off one pass by name.

Errors

For a name that is not a pass.

pub fn is_disabled(&self, name: &str) -> bool

Whether the pass by that name has been turned off.

Trait Implementations

impl Clone for Context

fn clone(&self) -> Context

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Context

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Context

fn default() -> Context

Returns the “default value” for a type.