sql: crdb_internal.ranges{,no_leases} does not interoperate correctly with user-defined schemas

[jordanlewis]

There is no disambiguating schema_name column in these tables, but there should be. The consequence of the lack of this is as follows:

demo@127.0.0.1:26257/defaultdb> create schema s;
CREATE SCHEMA

Time: 23ms total (execution 8ms / network 14ms)

demo@127.0.0.1:26257/defaultdb> create table t1 (a) as select 1;
CREATE TABLE AS

Time: 35ms total (execution 4ms / network 31ms)

demo@127.0.0.1:26257/defaultdb> create table s.t1 (a) as select 1;
CREATE TABLE AS

Time: 27ms total (execution 3ms / network 24ms)

demo@127.0.0.1:26257/defaultdb>
demo@127.0.0.1:26257/defaultdb>
demo@127.0.0.1:26257/defaultdb>
demo@127.0.0.1:26257/defaultdb> select * from crdb_Internal.ranges_no_leases where table_name='t1' and database_name='defaultdb';
  range_id | start_key | start_pretty | end_key  | end_pretty | database_name | table_name | index_name | replicas |    replica_localities    | learner_replicas | split_enforced_until
-----------+-----------+--------------+----------+------------+---------------+------------+------------+----------+--------------------------+------------------+-----------------------
        38 | \277      | /Table/55    | \300     | /Table/56  | defaultdb     | t1         |            | {1}      | {"region=us-east1,az=b"} | {}               | NULL
        39 | \300      | /Table/56    | \377\377 | /Max       | defaultdb     | t1         |            | {1}      | {"region=us-east1,az=b"} | {}               | NULL
(2 rows)

In addition, I feel like this table should also contain a table id - it'll just make things easier to join against other tables.

[jordanlewis]

In fact, if we included the table id, we could implement an efficient virtual index on this table, which would obviate the need to collect all descriptors just to get the range information for a single table, which I think is relatively common.