9.14. UUID Functions
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## 9.14. UUID Functions #

Table 9.45 shows the PostgreSQL functions that can be used to generate UUIDs.

Table 9.45. UUID Generation Functions

Function Description Example(s)
`gen_random_uuid` ( ) → `uuid` `uuidv4` ( ) → `uuid` Generates a version 4 (random) UUID `gen_random_uuid()` → `5b30857f-0bfa-48b5-ac0b-5c64e28078d1` `uuidv4()` → `b42410ee-132f-42ee-9e4f-09a6485c95b8`
`uuidv7` ( [ `shift` `interval` ] ) → `uuid` Generates a version 7 (time-ordered) UUID. The timestamp is computed using UNIX timestamp with millisecond precision + sub-millisecond timestamp + random. The optional parameter `shift` will shift the computed timestamp by the given `interval`. Infinite interval values are not accepted. The shifted timestamp must fall within the range supported by UUID version 7's 48-bit millisecond timestamp field: from 1970-01-01 00:00:00 UTC to approximately year 10889. An error is raised if the resulting timestamp is outside this range. `uuidv7()` → `019535d9-3df7-79fb-b466-fa907fa17f9e`

### Note

The uuid-ossp module provides additional functions that implement other standard algorithms for generating UUIDs.

Table 9.46 shows the PostgreSQL functions that can be used to extract information from UUIDs.

Table 9.46. UUID Extraction Functions

Function Description Example(s)
`uuid_extract_timestamp` ( `uuid` ) → `timestamp with time zone` Extracts a `timestamp with time zone` from a UUID of version 1 or 7. For other versions, this function returns null. Note that the extracted timestamp is not necessarily exactly equal to the time the UUID was generated; this depends on the implementation that generated the UUID. `uuid_extract_timestamp('019535d9-3df7-79fb-b466-​fa907fa17f9e'::uuid)` → `2025-02-23 21:46:24.503-05`
`uuid_extract_version` ( `uuid` ) → `smallint` Extracts the version from a UUID of one of the variants described by RFC 9562. For other variants, this function returns null. For example, for a UUID generated by `gen_random_uuid()`, this function will return 4. `uuid_extract_version('41db1265-8bc1-4ab3-992f-​885799a4af1d'::uuid)` → `4` `uuid_extract_version('019535d9-3df7-79fb-b466-​fa907fa17f9e'::uuid)` → `7`

PostgreSQL also provides the usual comparison operators shown in Table 9.1 for UUIDs.

See Section 8.12 for details on the data type `uuid` in PostgreSQL.

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