Struct QueryLimits 

pub struct QueryLimits {
    pub memory_bytes: Option<usize>,
    pub timeout: Option<Duration>,
    pub max_rows: Option<usize>,
    pub max_bytes: Option<usize>,
}

Bounds on what one query may consume and return. None means unlimited.

Fields

memory_bytes: Option<usize>

Memory pool for the whole session, in bytes; every query draws from it and fails with Resources exhausted instead of growing the process. With a cap set, spilling to disk is disabled too, so a hostile query fails fast rather than filling the disk.

timeout: Option<Duration>

Wall-clock budget for planning plus execution of one query.

max_rows: Option<usize>

Most rows a result may carry; the rest is dropped and the result marked truncated.

max_bytes: Option<usize>

Most bytes (Arrow in-memory size) a result may carry; same truncation rule.

Implementations

impl QueryLimits

pub const SAFE_MEMORY_BYTES: usize

The CLI defaults: 2 GiB pool, 60 s, 10 000 rows, 16 MiB.

pub const SAFE_TIMEOUT: Duration

See Self::safe.

pub const SAFE_MAX_ROWS: usize = 10_000

See Self::safe.

pub const SAFE_MAX_BYTES: usize

See Self::safe.

pub fn unlimited() -> QueryLimits

No limits at all: the pre-0.2 behaviour, and the default of AppState.

pub fn safe() -> QueryLimits

Defaults that keep one query from taking the machine down; what the CLI uses.

pub fn session_context(&self) -> Result<SessionContext, String>

A session whose memory pool honours Self::memory_bytes (unbounded when None). Register tables into this context, then build the state with it.

Trait Implementations

impl Clone for QueryLimits

fn clone(&self) -> QueryLimits

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for QueryLimits

impl Debug for QueryLimits

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

Formats the value using the given formatter.

impl Default for QueryLimits

fn default() -> QueryLimits

Returns the “default value” for a type.

impl Eq for QueryLimits

impl PartialEq for QueryLimits

fn eq(&self, other: &QueryLimits) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for QueryLimits