Merge pull request #249678 from mulander/fix-flex-pgvector-usage

Fix instructions for enabling/dropping pgvector

Author: v-ccolin

articles/postgresql/flexible-server/how-to-use-pgvector.md

@@ -19,14 +19,16 @@ ms.date: 05/09/2023
 
 ## Enable extension
 
-To install the extension, run the [CREATE EXTENSION](https://www.postgresql.org/docs/current/static/sql-createextension.html) command from the psql tool to load the packaged objects into your database.
+Before you can enable `pgvector` on your Flexible Server, you need to add it to your allowlist as described in [how to use PostgreSQL extensions](./concepts-extensions.md#how-to-use-postgresql-extensions) and check if it's correctly added by running `SHOW azure.extensions;`.
+
+Then you can install the extension, by connecting to your target database and running the [CREATE EXTENSION](https://www.postgresql.org/docs/current/static/sql-createextension.html) command. You need to repeat the command separately for every database you want the extension to be available in.
 
 ```postgresql
 CREATE EXTENSION vector;
 ```
 
 > [!Note]
-> To disable an extension use `drop_extension()`
+> To remove the extension from the currently connected database use `DROP EXTENSION vector;`.
 
 [!INCLUDE [`pgvector`](../../cosmos-db/postgresql/includes/pgvector-basics.md)]