pub struct ColumnIndex {
    pub null_pages: Vec<bool>,
    pub min_values: Vec<Vec<u8>>,
    pub max_values: Vec<Vec<u8>>,
    pub boundary_order: BoundaryOrder,
    pub null_counts: Option<Vec<i64>>,
}
Expand description

Description for ColumnIndex. Each [i] refers to the page at OffsetIndex.page_locations[i]

Fields§

§null_pages: Vec<bool>

A list of Boolean values to determine the validity of the corresponding min and max values. If true, a page contains only null values, and writers have to set the corresponding entries in min_values and max_values to byte[0], so that all lists have the same length. If false, the corresponding entries in min_values and max_values must be valid.

§min_values: Vec<Vec<u8>>

Two lists containing lower and upper bounds for the values of each page determined by the ColumnOrder of the column. These may be the actual minimum and maximum values found on a page, but can also be (more compact) values that do not exist on a page. For example, instead of storing ““Blart Versenwald III”, a writer may set min_values[i]=“B”, max_values[i]=“C”. Such more compact values must still be valid values within the column’s logical type. Readers must make sure that list entries are populated before using them by inspecting null_pages.

§max_values: Vec<Vec<u8>>§boundary_order: BoundaryOrder

Stores whether both min_values and max_values are orderd and if so, in which direction. This allows readers to perform binary searches in both lists. Readers cannot assume that max_values[i] <= min_values[i+1], even if the lists are ordered.

§null_counts: Option<Vec<i64>>

A list containing the number of null values for each page *

Implementations§

Trait Implementations§

Available on crate feature async only.
Returns a copy of the value. Read more
Performs copy-assignment from source. Read more
Formats the value using the given formatter. Read more
Feeds this value into the given Hasher. Read more
Feeds a slice of this type into the given Hasher. Read more
This method returns an Ordering between self and other. Read more
Compares and returns the maximum of two values. Read more
Compares and returns the minimum of two values. Read more
Restrict a value to a certain interval. Read more
This method tests for self and other values to be equal, and is used by ==.
This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.
This method returns an ordering between self and other values if one exists. Read more
This method tests less than (for self and other) and is used by the < operator. Read more
This method tests less than or equal to (for self and other) and is used by the <= operator. Read more
This method tests greater than (for self and other) and is used by the > operator. Read more
This method tests greater than or equal to (for self and other) and is used by the >= operator. Read more

Auto Trait Implementations§

Blanket Implementations§

Gets the TypeId of self. Read more
Immutably borrows from an owned value. Read more
Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

The resulting type after obtaining ownership.
Creates owned data from borrowed data, usually by cloning. Read more
Uses borrowed data to replace owned data, usually by cloning. Read more
The type returned in the event of a conversion error.
Performs the conversion.
The type returned in the event of a conversion error.
Performs the conversion.