ColumnIndex
Optional statistics for each data page in a ColumnChunk.
Forms part the page index, along with OffsetIndex.
If this structure is present, OffsetIndex must also be present.
For each field in this structure,
Properties
- $_TSPEC : mixed
- $boundary_order : int
- Stores whether both min_values and max_values are ordered 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.
- $definition_level_histograms : array<string|int, int>
- Same as repetition_level_histograms except for definitions levels.
- $isValidate : mixed
- $max_values : array<string|int, string>
- $min_values : array<string|int, string>
- 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".
- $null_counts : array<string|int, int>
- A list containing the number of null values for each page.
- $null_pages : array<string|int, 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.
- $repetition_level_histograms : array<string|int, int>
- Contains repetition level histograms for each page concatenated together. The repetition_level_histogram field on SizeStatistics contains more details.
Methods
- __construct() : mixed
- getName() : mixed
- read() : mixed
- write() : mixed
Properties
$_TSPEC
public
static mixed
$_TSPEC
= [1 => ['var' => 'null_pages', 'isRequired' => true, 'type' => \Thrift\Type\TType::LST, 'etype' => \Thrift\Type\TType::BOOL, 'elem' => ['type' => \Thrift\Type\TType::BOOL]], 2 => ['var' => 'min_values', 'isRequired' => true, 'type' => \Thrift\Type\TType::LST, 'etype' => \Thrift\Type\TType::STRING, 'elem' => ['type' => \Thrift\Type\TType::STRING]], 3 => ['var' => 'max_values', 'isRequired' => true, 'type' => \Thrift\Type\TType::LST, 'etype' => \Thrift\Type\TType::STRING, 'elem' => ['type' => \Thrift\Type\TType::STRING]], 4 => ['var' => 'boundary_order', 'isRequired' => true, 'type' => \Thrift\Type\TType::I32, 'class' => '\Flow\Parquet\Thrift\BoundaryOrder'], 5 => ['var' => 'null_counts', 'isRequired' => false, 'type' => \Thrift\Type\TType::LST, 'etype' => \Thrift\Type\TType::I64, 'elem' => ['type' => \Thrift\Type\TType::I64]], 6 => ['var' => 'repetition_level_histograms', 'isRequired' => false, 'type' => \Thrift\Type\TType::LST, 'etype' => \Thrift\Type\TType::I64, 'elem' => ['type' => \Thrift\Type\TType::I64]], 7 => ['var' => 'definition_level_histograms', 'isRequired' => false, 'type' => \Thrift\Type\TType::LST, 'etype' => \Thrift\Type\TType::I64, 'elem' => ['type' => \Thrift\Type\TType::I64]]]
$boundary_order
Stores whether both min_values and max_values are ordered 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.
public
int
$boundary_order
$definition_level_histograms
Same as repetition_level_histograms except for definitions levels.
public
array<string|int, int>
$definition_level_histograms
$isValidate
public
static mixed
$isValidate
= false
$max_values
public
array<string|int, string>
$max_values
$min_values
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".
public
array<string|int, string>
$min_values
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.
$null_counts
A list containing the number of null values for each page.
public
array<string|int, int>
$null_counts
Writers SHOULD always write this field even if no null values are present or the column is not nullable. Readers MUST distinguish between null_counts not being present and null_count being 0. If null_counts are not present, readers MUST NOT assume all null counts are 0.
$null_pages
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.
public
array<string|int, bool>
$null_pages
$repetition_level_histograms
Contains repetition level histograms for each page concatenated together. The repetition_level_histogram field on SizeStatistics contains more details.
public
array<string|int, int>
$repetition_level_histograms
When present the length should always be (number of pages * (max_repetition_level + 1)) elements.
Element 0 is the first element of the histogram for the first page. Element (max_repetition_level + 1) is the first element of the histogram for the second page.
Methods
__construct()
public
__construct([mixed $vals = null ]) : mixed
Parameters
- $vals : mixed = null
getName()
public
getName() : mixed
read()
public
read(mixed $input) : mixed
Parameters
- $input : mixed
write()
public
write(mixed $output) : mixed
Parameters
- $output : mixed