Basic Data Types

Data types are configured within the datatype object using the object type.

"settings": {
   "output_columns": [
        {
            "name": "a_string_column",
            "datatype": {
                "type": "string",
                .........

Basic Types

The following are supported.

Type	Indexed	Nullable	Description	Stored as
boolean	Yes (Default)	Yes	Converted to a `uint8` prior to storage. The case-insensitive strings `"false"` or `"0"` get converted to `0`. Any other non-`0` value gets converted to `1`.	`uint8`
double	No (can not be indexed).	Yes	A 64-bit floating-point number.	`float64`
int8	Yes (Default)	Yes	A signed 8-bit integer (`-128` : `127`).	`int8`
int32	Yes (Default)	Yes	A signed 32-bit integer (`-2147483648` : `2147483647`).	`int32`
int64	Yes (Default)	Yes	A signed 64-bit integer (`-9223372036854775808` : `9223372036854775807`).	`int64`
string	Yes (Default)	Yes	A variable-length string. Equivalent to `VARCHAR` or `CLOB` in other data systems.	`string`
uint8	Yes (Default)	Yes	An unsigned 8-bit integer (`0` : `255`).	`uint8`
uint32	Yes (Default)	Yes	An unsigned 32-bit integer (`0` : `4294967295`).	`uint32`
uint64	Yes (Default)	Yes	An unsigned 64-bit integer (`0` : `18446744073709551615`).	`uint64`

Nullables

Nullables in Hydrolix are not directly defined in the type and instead are defined by the default setting within the datatype object. By default all columns (except primary columns) are nullable, to make a field non-nullable a default is set forcing a value if one is not provided.

It should be noted that the default setting should be appropriate to the type, e.g. setting "" (empty string) for the type uint64 will cause unexpected and likely unwanted behaviours.

📘
Performance, Nulls and Strings
Hydrolix has seen performance improvements in query times if nulls are not required. For example setting a string default set as "" (empty string).

"settings": {
   "output_columns": [
     {
            "name": "nullable_string",
            "datatype": {
                "type": "string",
                "default": null
            }
        },
        {
            "name": "non_nullable_string",
            "datatype": {
                "type": "string",
                "default": ""
            }
        },
        {
            "name": "nullable_uint64",
            "datatype": {
                "type": "uint64",
                "default": null
            }
        },
        {
            "name": "non_nullable_string",
            "datatype": {
                "type": "uint64",
                "default": 0
            }
        },
     ..................

Indexing

Hydrolix has been specifically designed to index by default, without the traditional penalties found in older data platforms. It is therefore strongly suggested that the user should only turn off indexing of a column when absolutely necessary. By default Hydrolix indexes all data types except doubles.

Indexing is turned (on and) off within the data type descriptor in Output Columns.

"settings": {
   "output_columns": [
        {
            "name": "indexed_string_column",
            "datatype": {
                "type": "string",
                "index": true
            }
        },
        {
            "name": "not_indexed_string_column",
            "datatype": {
                "type": "string",
                "index": false
            }
        }
    ]
}

Updated 5 months ago

Basic Types

Nullables

📘Performance, Nulls and Strings

Indexing

📘
Performance, Nulls and Strings