Crate mz_repr

Fundamental data representation.

This module contains the types for representing data in Materialize that all layers of the stack can understand. Think of it as the lingua franca: individual layers may use different representations internally, but they all agree to use this representation at their boundaries.

• The core value type is the Datum enum, which represents a literal value.
• Row extends a Datum horizontally, and has features for efficiently doing so.
• RelationDesc describes what it takes to extend a Row vertically, and corresponds most closely to what is returned from querying our dataflows

Re-exports

• pub use crate::global_id::GlobalId;

Modules

• adt
  Abstract data types.
• antichain
• chrono
  Custom proptest::strategy::Strategy implementations and Protobuf types for the chrono fields used in the codebase.
• explain
  A set of traits for modeling things that can be explained by a SQL EXPLAIN statement.
• global_id
• namespaces
  Namespace constants to share between high- and low-levels of the system.
• role_id
• stats
• strconv
  Routines for converting datum values to and from their string representation.
• url
  Custom Protobuf types for the url crate.

Structs

• ArrayRustType
  A new type that wraps a Vec that is used to differentiate the target Datum between Arrays and Lists. The target of this type is Array.
• ColumnName
  The name of a column in a RelationDesc.
• ColumnType
  The type of a Datum.
• DatumList
  A sequence of Datums
• DatumMap
  A mapping from string keys to Datums
• DatumVec
  A re-useable vector of Datum with no particular lifetime.
• DatumVecBorrow
  A borrowed allocation of Datum with a specific lifetime.
• NotNullViolation
  Expression violated not-null constraint on named column
• PropArray
• PropDict
• PropList
• ProtoColumnName
• ProtoColumnType
• ProtoRelationDesc
• ProtoRelationType
• ProtoRow
• ProtoScalarType
• RelationDesc
  A description of the shape of a relation.
• RelationType
  The type of a relation.
• Row
  A packed representation for Datums.
• RowArena
  RowArena is used to hold on to temporary Rows for functions like eval that need to create complex Datums but don’t have a Row to put them in yet.
• RowDecoder
  An implementation of PartDecoder for Row.
• RowEncoder
  An implementation of PartEncoder for Row.
• RowPacker
  Packs datums into a Row.
• RowRef
  A wrapper around a byte slice that guarantees the data are row-formatted.
• Timestamp
  System-wide timestamp type.

Enums

• Datum
  A single value.
• PropDatum
  A mirror type for Datum that can be proptest-generated.
• ScalarBaseType
• ScalarType
  The type of a Datum.

Statics

• VARIABLE_LENGTH_ROW_ENCODING
  Whether to encode rows with variable-length integers and timestamps. This is thought to incur a slight (a few percent) regression in CPU efficiency, in exchange for improved memory usage.

Traits

• AsColumnType
  Types that implement this trait can be stored in an SQL column with the specified ColumnType
• DatumDecoderT
  An enum_dispatch companion for DatumDecoder.
• DatumEncoderT
  An enum_dispatch companion for DatumEncoder.
• DatumToPersist
  Implementation of mapping between mz Datum and persist Data.
• DatumToPersistFn
  FnOnce<T: DatumToPersist>() -> R
• DatumType
  A bridge between native Rust types and SQL runtime types represented in Datums
• TimestampManipulation

Functions

• arb_datum
  Generate an arbitrary PropDatum.
• arb_range_type
• datum_list_size
  Number of bytes required by a list of datums. This computes the size that would be required if the given datums were packed into a list.
• datum_size
  Number of bytes required by the datum. This is used to optimistically pre-allocate buffers for packing rows.
• datum_size_deterministic
  Number of bytes required by the datum, given the value of VARIABLE_LENGTH_ENCODING.
• datums_size
  Number of bytes required by a sequence of datums.
• datums_size_deterministic
  Number of bytes required by a sequence of datums.
• is_no_stats_type
  This returns true if we don’t care to keep stats for this column type (for now). We’ll have to remove this if/when we start actually using the schema’d part encoding.
• row_size_deterministic
  Return the number of bytes these Datums would use if packed as a Row.

Type Definitions

• Diff
  System-wide record count difference type.