Struct TableMeta 

pub struct TableMeta {
    pub entity_identity: Option<BTreeMap<String, String>>,
    /* private fields */
}

High-level table metadata stored in the log.

This describes the table kind, a logical schema (optional in v0.1), and basic bookkeeping fields.

Fields

entity_identity: Option<BTreeMap<String, String>>

v0.1: If TimeIndexSpec.entity_columns is non-empty, we pin a single entity identity per table (map keyed by column name).

Implementations

impl TableMeta

pub fn kind(&self) -> &TableKind

Returns the table kind (e.g. time series or generic).

pub fn logical_schema(&self) -> Option<&LogicalSchema>

Returns the optional logical schema if it has been set.

pub fn created_at(&self) -> DateTime<Utc>

Returns the UTC timestamp when the table was created.

pub fn format_version(&self) -> u32

Returns the on-disk table metadata format version.

pub fn new_time_series(index: TimeIndexSpec) -> TableMeta

Convenience constructor for a time-series table.

• Fills created_at with Utc::now().
• Fills format_version with TABLE_FORMAT_VERSION.
• Leaves logical_schema as None; it will be adopted from the first appended segment in v0.1.

pub fn new_time_series_with_schema( index: TimeIndexSpec, logical_schema: LogicalSchema, ) -> TableMeta

Variant that lets you explicitly pass a logical schema up front.

pub fn arrow_schema_ref(&self) -> Result<Arc<Schema>, TableMetaSchemaError>

Convert the table’s logical schema to a shared Arrow SchemaRef.

Returns TableMetaSchemaError::MissingCanonicalSchema if the schema has not yet been established for the table.

Trait Implementations

impl Clone for TableMeta

fn clone(&self) -> TableMeta

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for TableMeta

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for TableMeta

fn deserialize<__D>( __deserializer: __D, ) -> Result<TableMeta, <__D as Deserializer<'de>>::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for TableMeta

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Serialize for TableMeta

fn serialize<__S>( &self, __serializer: __S, ) -> Result<<__S as Serializer>::Ok, <__S as Serializer>::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Eq for TableMeta

impl StructuralPartialEq for TableMeta