Extensions
Schema Cache
To avoid having to continuously fetch schema data from PostgreSQL, DuckDB keeps schema information – such as the names of tables, their columns, etc. – cached. If changes are made to the schema through a different connection to the PostgreSQL instance, such as new columns being added to a table, the cached schema information might be outdated. In this case, the function `pg_clear_cache` can be executed to clear the internal caches.  
```sql
CALL pg_clear_cache();
```  
> **Deprecated.  ** The old `postgres_attach` function is deprecated. It is recommended to switch over to the new `ATTACH` syntax.