Struct QueryContext 

pub struct QueryContext { /* private fields */ }

Query context

The context for each query request is created whenever the query request is received by the query engine. This context object is visible to the parser, planner, optimizer, and executor.

Responsibilities

• Query request context (session information, request parameters)
• Request-scoped cancellation token (shared with the execution runtime and the process-level query registry — one token for all cancellation)
• ID generation for query execution
• Space information management (space info, character set)
• Optional arena allocator for high-performance temporary allocations

Creation

Use QueryContext::new for simple cases or QueryContext::builder for complex configuration.

Implementations

impl QueryContext

pub fn new(rctx: Arc<QueryRequestContext>) -> Self

Create a new query context with default configuration.

For complex configuration (arena allocation, custom ID generator, etc.), use QueryContext::builder instead.

pub fn builder(rctx: Arc<QueryRequestContext>) -> QueryContextBuilder

Create a builder for complex configuration.

Example

let ctx = QueryContext::builder(rctx)
    .with_space_info(space_info)
    .with_charset_info(charset_info)
    .with_arena()
    .build();

pub fn request_context(&self) -> &QueryRequestContext

Obtain the context of the query request.

pub fn request_context_arc(&self) -> Arc<QueryRequestContext>

The Arc reference that provides the context for the query request.

pub fn rctx(&self) -> &QueryRequestContext

Obtain the context of the query request (compatible with old code)

pub fn cancel_token(&self) -> CancelToken

The request-scoped cancellation token.

Threaded into the execution runtime and query registry at instantiation so all cancellation paths share one source of truth.

pub fn charset_info(&self) -> Option<&CharsetInfo>

Obtaining character set information

pub fn set_charset_info(&mut self, charset_info: CharsetInfo)

Setting character set information

pub fn snapshot_ts(&self) -> Option<Timestamp>

The MVCC snapshot timestamp for consistent reads within explicit transactions.

None means auto-commit single-statement execution, which reads the current version of the data.

pub fn isolation_level(&self) -> Option<TransactionIsolationLevel>

The transaction isolation level for this execution, when running inside an explicit transaction.

pub fn password_history_depth(&self) -> usize

The retained password-history depth for user-management operations planned under this context.

pub fn authenticated_user(&self) -> Option<&str>

The authenticated user that issued this query, when the request came from an authenticated session.

Self-service password changes omit the username in the statement; the planner backfills it from here so the execution chain targets the caller instead of failing on an empty username.

pub fn gen_id(&self) -> i64

Generate an ID.

pub fn current_id(&self) -> i64

Retrieve the current ID value (without incrementing it).

pub fn space_info(&self) -> Option<&SpaceInfo>

Obtain the current spatial information

pub fn set_space_info(&mut self, space_info: SpaceInfo)

Set the current space information

pub fn space_id(&self) -> Option<u64>

Obtain the ID of the current space.

pub fn space_name(&self) -> Option<String>

Get the name of the current space.

pub fn mark_killed(&self)

Mark this query as killed.

Cancels the request-scoped token shared with the execution runtime and the query registry, so running operators abort at the next cooperative cancellation check and KILL QUERY observability reflects the state.

pub fn is_killed(&self) -> bool

Check whether this query has been killed/cancelled.

pub fn exist_parameter(&self, param: &str) -> bool

Check whether the parameters exist.

pub fn query(&self) -> &str

Obtain the query string

pub fn parameters(&self) -> &HashMap<String, Value>

Obtain parameters

pub fn reset(&mut self)

Reset the query context

pub fn has_arena(&self) -> bool

Check if arena allocation is enabled for this query’s execution.

Trait Implementations

impl Debug for QueryContext

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

Formats the value using the given formatter.

impl Default for QueryContext

fn default() -> Self

Returns the “default value” for a type.