UUID Data Type

Stores universally unique identifiers (UUIDs). UUIDs are 16-byte (128-bit) numbers used to uniquely identify records. To generate UUIDs, Vertica provides the function UUID_GENERATE, which returns UUIDs based on high-quality randomness from /dev/urandom.

Syntax

UUID

UUID Input and Output Formats

UUIDs support input of case-insensitive string literal formats, as specified by RFC 4122. In general, a UUID is written as a sequence of hexadecimal digits, in several groups optionally separated by hyphens, for a total of 32 digits representing 128 bits.

The following input formats are valid:

6bbf0744-74b4-46b9-bb05-53905d4538e7
{6bbf0744-74b4-46b9-bb05-53905d4538e7}
6BBF074474B446B9BB0553905D4538E7
6BBf-0744-74B4-46B9-BB05-5390-5D45-38E7

On output, Vertica always uses the following format:

xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx

For example, the following table defines column cust_id as a UUID:

=> CREATE TABLE public.Customers
(
    cust_id uuid,
    lname varchar(36),
    fname varchar(24)
);

The following input for cust_id uses several valid formats:

=>  COPY Customers FROM STDIN;
Enter data to be copied followed by a newline.
End with a backslash and a period on a line by itself.
>> {cede66b7-3d29-4da6-b700-871fc0ac57be}|Kearney|Thomas
>> 34462732ed5649838f3be735b0c32d50|Pham|Duc
>> 9fb0-1de0-1d63-4d09-9415-90e0-b4e9-3b9a|Steinberg|Jeremy
>> \.

On querying this table, Vertica formats all cust_id data in the same way:

=> SELECT cust_id, fname, lname FROM Customers;
                cust_id                | fname  |   lname
--------------------------------------+--------+-----------
 9fb01de0-1d63-4d09-9415-90e0b4e93b9a | Jeremy | Steinberg
 34462732-ed56-4983-8f3b-e735b0c32d50 | Duc    | Pham
 cede66b7-3d29-4da6-b700-871fc0ac57be | Thomas | Kearney
(3 rows)

Generating UUIDs

You can use the Vertica function UUID_GENERATE to automatically generate UUIDs that uniquely identify table records. For example:

=> INSERT INTO Customers SELECT UUID_GENERATE(),'Rostova','Natasha';
OUTPUT -------- 1 (1 row) => COMMIT; COMMIT => SELECT cust_id, fname, lname FROM Customers; cust_id | fname | lname --------------------------------------+---------+----------- 9fb01de0-1d63-4d09-9415-90e0b4e93b9a | Jeremy | Steinberg 34462732-ed56-4983-8f3b-e735b0c32d50 | Duc | Pham cede66b7-3d29-4da6-b700-871fc0ac57be | Thomas | Kearney 9aad6757-fe1b-473a-a109-b89b7b358c69 | Natasha | Rostova (4 rows)

NULL Input and Output

The following string is reserved as NULL for UUID columns:

00000000-0000-0000-0000-000000000000

Vertica always renders NULL as blank.

The following COPY statements insert NULL values into the UUID column, explicitly and implicitly:

=>  COPY Customers FROM STDIN NULL AS 'null';
Enter data to be copied followed by a newline.
End with a backslash and a period on a line by itself.
>> null|Doe|Jane
>> 00000000-0000-0000-0000-000000000000|Man|Nowhere
>> \.
=>  COPY Customers FROM STDIN;
>> |Doe|John
>> \.  

In all cases, Vertica renders NULL as blank:

=> SELECT cust_id, fname, lname FROM Customers WHERE cust_id IS NULL;
 cust_id |  fname  | lname
---------+---------+-------
         | Nowhere | Man
         | Jane    | Doe
         | John    | Doe
(3 rows)

Usage Restrictions

UUID data types only support relational operators and functions that are also supported by CHAR and VARCHAR data types—for example, MIN, MAX, and COUNT. UUID data types do not support mathematical operators or functions, such as SUM and AVG.

 


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