Module database 

Module with database related functionality. In particular, this module contains the accessor traits and the OwnedTable type along with some utility functions to convert between Arrow and OwnedTable.

Re-exports

pub use crate::base::arrow::arrow_array_to_column_conversion::ArrayRefExt;

pub use crate::base::arrow::arrow_array_to_column_conversion::ArrowArrayToColumnConversionError;

pub use crate::base::arrow::owned_and_arrow_conversions::OwnedArrowConversionError;

pub use crate::base::arrow::scalar_and_i256_conversions;

Modules

arrow_schema_utility

This module provides utility functions for working with Arrow schemas in the context of Proof of SQL. It includes functionality to convert Arrow schemas to PoSQL-compatible formats.

owned_table_utility

Utility functions for creating OwnedTables and OwnedColumns. These functions are primarily intended for use in tests.

table_utility

Utility functions for creating Tables and Columns. These functions are primarily intended for use in tests.

Structs

ColumnField

This type is used to represent the metadata of a column in a table. Namely: it’s name and type.

ColumnRef

Reference of a SQL column

OwnedTable

A table of data, with schema included. This is simply a map from Ident to OwnedColumn, where columns order matters. This is primarily used as an internal result that is used before converting to the final result in either Arrow format or JSON. This is the analog of an arrow RecordBatch.

OwnedTableTestAccessor

A test accessor that uses OwnedTable as the underlying table type. Note: this is intended for testing and examples. It is not optimized for performance, so should not be used for benchmarks or production use-cases.

Table

A table of data, with schema included. This is simply a map from Ident to Column, where columns order matters. This is primarily used as an internal result that is used before converting to the final result in either Arrow format or JSON. This is the analog of an arrow RecordBatch.

TableEvaluation

The result of evaluating a table

TableOptions

Options for creating a table. Inspired by RecordBatchOptions

TableRef

Expression for an SQL table

TableTestAccessor

A test accessor that uses Table as the underlying table type. Note: this is intended for testing and examples. It is not optimized for performance, so should not be used for benchmarks or production use-cases.

TestSchemaAccessor

A simple in-memory SchemaAccessor for testing intermediate AST -> Provable AST conversion.

Enums

Column

Represents a read-only view of a column in an in-memory, column-oriented database.

ColumnOperationError

Errors from operations on columns.

ColumnType

Represents the supported data types of a column in an in-memory, column-oriented database.

ColumnarValue

The result of evaluating an expression.

LiteralValue

Represents a literal value.

OwnedColumn

Supported types for OwnedColumn

OwnedColumnError

Errors from operations related to OwnedColumns.

OwnedTableError

An error that occurs when working with tables.

ParseError

Errors encountered during the parsing process

TableOperationError

Errors from operations on tables.

Traits

CommitmentAccessor

Access commitments of database columns.

DataAccessor

Access database columns of an in-memory table span.

MetadataAccessor

Access metadata of a table span in a database.

SchemaAccessor

Access tables and their schemas in a database.

TestAccessor

A trait that defines the interface for a combined metadata, schema, commitment, and data accessor for unit testing or example purposes.

Functions

can_and_or_types

Verifies that two types can be used in a logical AND or OR expressions

can_not_type

Verifies that the NOT expr can be used on an expression

try_add_subtract_column_types

Determine the output type of an add or subtract operation if it is possible to add or subtract the two input types. If the types are not compatible, return an error.

try_add_subtract_column_types_with_scaling

Determine the output type of an add or subtract operation if it is possible to add or subtract the two input types. Scaling is allowed. If the types are not compatible, return an error.

try_cast_types

Verifies that from can be cast to to. For now, this supports a limited number of casts.

try_divide_column_types

Determine the output type of a division operation if it is possible to divide the two input types. If the types are not compatible, return an error.

try_equals_types

Verfies that the equality operator can be used on the two types

try_equals_types_with_scaling

Verfies that the equality operator can be used on the two types with scaling allowed

try_inequality_types

Verifies that two types can be compared using inequalities

try_inequality_types_with_scaling

Verifies that two types can be compared using inequalities with scaling allowed

try_multiply_column_types

Determine the output type of a multiplication operation if it is possible to multiply the two input types. If the types are not compatible, return an error.

try_scale_cast_types

Verifies that from can be cast to to. Casting can only be supported if the resulting data type is a superset of the input data type. For example Deciaml(6,1) can be cast to Decimal(7,1), but not vice versa.

Type Aliases

ColumnOperationResult

Result type for column operations

OwnedColumnResult

Result type for operations related to OwnedColumns.

TableOperationResult

Result type for table operations