This page gives an overview of the data types supported by Polypheny.
Scalar Types
| Type | Description |
|---|---|
| BIGINT | 8 bytes signed (two’s complement). Ranges from -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807. |
| BOOLEAN | 1-bit. Takes the value true and false. |
| DATE | Represents a date. Format: yyyy-mm-dd |
| DECIMAL | A decimal number is a number that can have a decimal point in it. This type has two arguments: precision (max. 64) and scale (max. 64). Precision is the total number of digits, scale is the number of digits to the right of the decimal point. The scale can not exceed the precision. If no arguments are provided, the default is 64,32. |
| DOUBLE | 8 bytes IEEE 754. Covers a range from 4.94065645841246544e-324d to 1.79769313486231570e+308d (positive or negative). |
| INTEGER | 4 bytes, signed (two’s complement). Covers a range from -2,147,483,648 to 2,147,483,647. |
| REAL | 4 bytes, IEEE 754. Covers a range from 1.40129846432481707e-45 to 3.40282346638528860e+38 (positive or negative). |
| SMALLINT | 2 bytes, signed (two’s complement). Covers a range from -32,768 to 32,767. |
| TEXT | UTF-8 String with a size of up to 1GB. |
| TIME | Represents a time of day without time zone. Optionally, precision can have a value between 0 and 3 specifying the number of fractional seconds. Format: hh:mm:ss.f |
| TIMESTAMP | Represents a combination of DATE and TIME values. Optionally, precision can have a value between 0 and 3 specifying the number of fractional seconds. Format: yyyy-mm-dd hh:mm:ss.f |
| TINYINT | 1 byte, signed (two’s complement). Covers a range from -128 to 127. |
| VARCHAR | UTF-8 String with variable length. The maximum length is specified as parameter. |
Array Types
An array is an ordered, contiguous collection that may contain duplicates. Polypheny supports arrays of all scalar types.
In Polypheny, arrays can have an arbitrary dimension and cardinality. Both are specified as arguments. Specifying -1 disables validation.
The dimension specifies how deep arrays can be nested. A dimension of one therefore means that nested arrays are not allowed while a dimension of two allows nested arrays but no nested arrays within nested arrays.
The cardinality specifies the number of elements (values and nested arrays) in every (nested) array.
Vector Types
A vector is a special form of an array. What is different to arrays, is that dimension is fixed to 1 and cardinality can only take values greater than 0. This forbids -1 to disable validation. Furthermore vectors cannot hold NULL elements. Since vectors do only have one parameter we speak of dimensions instead of cardinality in this context, this is not the dimension of an array described above.
Declaring a vector can be done with <base type> VECTOR(n). Only REAL, FLOAT and BOOLEAN are allowed as type. REAL and FLOAT result in a float vector, BOOLEAN in a bit vector. Any other base type is accepted by the parser but results in an ordinary array and not in a vector.
| Example | Description |
|---|---|
| REAL VECTOR(384) | float vector, 384 dimensions |
| BOOLEAN VECTOR(256) | bit vector, 256 dimensions |
Values can be inserted as ordinary arrays.
CREATE TABLE listing (
id INTEGER NOT NULL,
embedding REAL VECTOR(3),
PRIMARY KEY(id)
);
INSERT INTO listing VALUES (1, ARRAY[1.0, 2.0, 3.0]);
Multimedia and File Types
Polypheny natively supports storing files. In addition to the generic FILE data type
there are also additional types for multimedia content. Multimedia files are not checked
by their file extension, but by their content type.
See SimpleMagic.ContentType for more information.
| Type | Description |
|---|---|
| AUDIO | Accepted content types: AIFF, AUDIO/MPEG, MIDI, REAL/AUDIO, WAV |
| FILE | Accepts files of any type. |
| IMAGE | Accepted content types: APPLE_QUICKTIME_IMAGE, BMP, GIF, JPEG, JPEG 2000, PBM, PGM, PNG, PPM, SVG, TIFF |
| VIDEO | Accepted content types: APPLE_QUICKTIME_MOVIE, AVI, MNG, MP4A, MP4V, VIDEO/MPEG |
