Materialize v0.62

v0.62.0

Support adding individual subsources in the PostgreSQL source using the new ALTER SOURCE...ADD SUBSOURCE syntax.

Add the try_parse_monotonic_iso8601_timestamp function, which should be used in temporal filters involving string timestamps (e.g. extracted from jsonb columns) to benefit from filter pushdown optimization.

For a given JSON-formatted source, the following query cannot benefit from filter pushdown:
```
SELECT *
FROM foo
WHERE (data ->> 'timestamp')::timestamp > mz_now();
```
But can be optimized as:
```
SELECT *
FROM foo
WHERE try_parse_monotonic_iso8601_timestamp(data ->> 'timestamp') > mz_now();
```
It’s important to note that temporal filter pushdown is disabled by default. You must contact us to enable this feature in your Materialize region.
Improve and extend the base implementation of Role-based access control (RBAC):
- Add the pg_has_role function, which reports if a specified user has USAGE or MEMBER privileges for a specified role.
It’s important to note that role-based access control (RBAC) is disabled by default. You must contact us to enable this feature in your Materialize region.