| title |
|---|
Array Schema |
The current array schema version(>=10) is a folder called __schema located here:
my_array # array folder
| ...
|_ __schema # array schema folder
|_ <timestamped_name> # array schema file
|_ ...
The array schema folder can contain:
- Any number of array schema files with name
<timestamped_name>.- Note: the name does not include the format version.
The previous array schema version(<=9) has a file named __array_schema.tdb and is located here:
my_array # array folder
|_ ....
|_ __array_schema.tdb # array schema file
|_ ...
The array schema file consists of a single generic tile, with the following data:
| Field | Type | Description |
|---|---|---|
| Array version | uint32_t |
Format version number of the array schema |
| Allows dups | bool |
Whether or not the array allows duplicate cells |
| Array type | uint8_t |
Dense or sparse |
| Tile order | uint8_t |
Row or column major |
| Cell order | uint8_t |
Row or column major |
| Capacity | uint64_t |
For sparse fragments, the data tile capacity |
| Coords filters | Filter Pipeline | The filter pipeline used as default for coordinate tiles |
| Offsets filters | Filter Pipeline | The filter pipeline used for cell var-len offset tiles |
| Validity filters | Filter Pipeline | The filter pipeline used for cell validity tiles |
| Domain | Domain | The array domain |
| Num attributes | uint32_t |
Number of attributes in the array |
| Attribute 1 | Attribute | First attribute |
| … | … | … |
| Attribute N | Attribute | Nth attribute |
| Num labels | uint32_t |
Number of dimension labels in the array |
| Label 1 | Dimension Label | First dimension label |
| … | … | … |
| Label N | Dimension Label | Nth dimension label |
The domain has internal format:
| Field | Type | Description |
|---|---|---|
| Num dimensions | uint32_t |
Dimensionality/rank of the domain |
| Dimension 1 | Dimension | First dimension |
| … | … | … |
| Dimension N | Dimension | Nth dimension |
The dimension has internal format:
| Field | Type | Description |
|---|---|---|
| Dimension name length | uint32_t |
Number of characters in dimension name |
| Dimension name | uint8_t[] |
Dimension name character array |
| Dimension datatype | uint8_t |
Datatype of the coordinate values |
| Cell val num | uint32_t |
Number of coordinate values per cell. For variable-length dimensions, this is std::numeric_limits<uint32_t>::max() |
| Filters | Filter Pipeline | The filter pipeline used on coordinate value tiles |
| Domain size | uint64_t[] |
The domain size in bytes |
| Domain | uint8_t[] |
Byte array of length equal to domain size above, storing the min, max values of the dimension. |
| Null tile extent | uint8_t |
1 if the dimension has a null tile extent, else 0. |
| Tile extent | uint8_t[] |
Byte array of length equal to the dimension datatype size, storing the space tile extent of this dimension. |
The attribute has internal format:
| Field | Type | Description |
|---|---|---|
| Attribute name length | uint32_t |
Number of characters in attribute name |
| Attribute name | uint8_t[] |
Attribute name character array |
| Attribute datatype | uint8_t |
Datatype of the attribute values |
| Cell val num | uint32_t |
Number of attribute values per cell. For variable-length attributes, this is std::numeric_limits<uint32_t>::max() |
| Filters | Filter Pipeline | The filter pipeline used on attribute value tiles |
| Fill value size | uint64_t |
The size in bytes of the fill value |
| Fill value | uint8_t[] |
The fill value |
| Nullable | bool |
Whether or not the attribute can be null |
| Fill value validity | uint8_t |
The validity fill value |
| Order | uint8_t |
Order of the data stored in the attribute. This may be unordered, increasing or decreasing |
The dimension label has internal format:
| Field | Type | Description |
|---|---|---|
| Dimension index | uint32_t |
Index of the dimension the label is for |
| Label order | uint8_t |
Order of the label data |
| Dimension label name length | uint64_t |
Number of characters in the dimension label name |
| Dimension label name | uint8_t [] |
The name of the dimension label |
| Relative URI | uint8_t |
If the URI of the array the label data is stored in is relative to this array |
| URI length | uint64_t |
The number of characters in the URI |
| URI | uint8_t [] |
The URI the label data is stored in |
| Label attribute name length | uint32_t |
The length of the attribute name of the label data |
| Label attribute name | uint8_t [] |
The name of the attribute the label data is stored in |
| Label datatype | uint8_t |
The datatype of the label data |
| Label cell_val_num | uint32_t |
The number of values per cell of the label data. For variable-length labels, this is std::numeric_limits<uint32_t>::max() |
| Label domain size | uint64_t |
The size of the label domain |
| Label domain start size | uint64_t |
The size of the first value of the domain for variable-lenght datatypes. For fixed-lenght labels, this is 0 |
| Label domain data | uint8_t[] |
Byte array of length equal to domain size above, storing the min, max values of the dimension |
| Is external | uint8_t |
If the URI is not stored as part of this array |