feat: table route for metric engine

[MichaelScofield]

I hereby agree to the terms of the GreptimeDB CLA

What's changed and what's your intention?

Now metric engine table can be created. Basic insertion is supported:

mysql> create table physical_table(ts timestamp time index) engine = metric with (physical_metric_table = true);
Query OK, 0 rows affected (0.03 sec)

mysql> select * from information_schema.tables where engine = 'metric';
+---------------+--------------+----------------+------------+----------+--------+
| table_catalog | table_schema | table_name     | table_type | table_id | engine |
+---------------+--------------+----------------+------------+----------+--------+
| greptime      | public       | physical_table | BASE TABLE |     1044 | metric |
+---------------+--------------+----------------+------------+----------+--------+
1 row in set (0.48 sec)

mysql> create table l1(ts timestamp time index, i int) engine = metric with (on_physical_table = 'physical_table');
Query OK, 0 rows affected (0.05 sec)

mysql> insert into l1 values (1,1);
Query OK, 1 row affected (0.01 sec)

mysql> select * from l1;
+----------------------------+------+
| ts                         | i    |
+----------------------------+------+
| 1970-01-01 00:00:00.001000 |    1 |
+----------------------------+------+
1 row in set (0.03 sec)

mysql> create table l2(ts timestamp time index, s string) engine = metric with (on_physical_table = 'physical_table');
Query OK, 0 rows affected (0.05 sec)

mysql> insert into l2 values(1,"a");
Query OK, 1 row affected (0.00 sec)

Basic query is also supported:

mysql> select * from l2;
+----------------------------+------+
| ts                         | s    |
+----------------------------+------+
| 1970-01-01 00:00:00.001000 | NULL | <-- Not expected line, might be related to some unfinished metric engine works though. Ignore it now.
| 1970-01-01 00:00:00.001000 | a    |
+----------------------------+------+
2 rows in set (0.01 sec)

Will add more tests in the next PR.

Checklist

• I have written the necessary rustdoc comments.
• I have added the necessary unit tests and integration tests.
• This PR does not require documentation updates.

Refer to a related PR or issue link (optional)

#2864

[codecov]

Codecov Report

Attention: 98 lines in your changes are missing coverage. Please review.

Comparison is base (5c66ce6) 85.66% compared to head (99bd516) 85.12%.
Report is 2 commits behind head on main.

Additional details and impacted files

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- Coverage   85.66%   85.12%   -0.55%     
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  Files         805      804       -1     
  Lines      130889   131031     +142     
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- Hits       112132   111536     -596     
- Misses      18757    19495     +738     

[fengjiachun]

@waynexia PTAL

[fengjiachun]

LGTM

[fengjiachun]

I conducted a test: after restarting, the two logical tables l1 and l2 could not be found.

[MichaelScofield]

@fengjiachun PTAL

[waynexia]

This LGTM in general 👍