Add Generate Random UUIDs Without An Extension as a postgres til

README.md

@@ -10,7 +10,7 @@ pairing with smart people at Hashrocket.
 
 For a steady stream of TILs, [sign up for my newsletter](https://tinyletter.com/jbranchaud).
 
-_1008 TILs and counting..._
+_1009 TILs and counting..._
 
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@@ -521,6 +521,7 @@ _1008 TILs and counting..._
 - [Find The Location Of Postgres Config Files](postgres/find-the-location-of-postgres-config-files.md)
 - [Fizzbuzz With Common Table Expressions](postgres/fizzbuzz-with-common-table-expressions.md)
 - [Generate A UUID](postgres/generate-a-uuid.md)
+- [Generate Random UUIDs Without An Extension](postgres/generate-random-uuids-without-an-extension.md)
 - [Generate Series Of Numbers](postgres/generate-series-of-numbers.md)
 - [Generating UUIDs With pgcrypto](postgres/generating-uuids-with-pgcrypto.md)
 - [Get The Size Of A Database](postgres/get-the-size-of-a-database.md)

postgres/generate-random-uuids-without-an-extension.md

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+# Generate Random UUIDs Without An Extension
+
+In other posts I've covered how to generate v4 random UUIDs in PostgreSQL
+[using the `uuid-ossp` extension](generate-a-uuid.md) as well as the more
+up-to-date method of [using the `pgcrypto`
+extension](generating-uuids-with-pgcrypto.md).
+
+As of PostgreSQL v13, you no longer need to add an extension for v4 UUID
+generation. It comes built-in as the `gen_random_uuid()` function.
+
+```sql
+> select gen_random_uuid();
+           gen_random_uuid
+--------------------------------------
+ 0aa72fe6-ede7-4ccf-b328-348becc58066
+(1 row)
+```
+
+If you need other non-v4 UUID functions, you'll have to stick with
+[uuid-ossp](https://www.postgresql.org/docs/current/uuid-ossp.html).