Add Partitioned DML

[yfuruyama]

Syntax:

PARTITIONED (UPDATE|DELETE) ...;

Example:

spanner> select * from Songs;
+----------+---------+---------+-------------------------+----------+-----------+
| SingerId | AlbumId | TrackId | SongName                | Duration | SongGenre |
+----------+---------+---------+-------------------------+----------+-----------+
| 2        | 1       | 1       | Let's Get Back Together | 182      | COUNTRY   |
| 2        | 1       | 2       | Starting Again          | 156      | ROCK      |
| 2        | 1       | 3       | I Knew You Were Magic   | 294      | BLUES     |
| 2        | 1       | 4       | 42                      | 185      | CLASSICAL |
| 2        | 1       | 5       | Blue                    | 238      | BLUES     |
| 2        | 1       | 6       | Nothing Is The Same     | 303      | BLUES     |
| 2        | 1       | 7       | The Second Time         | 255      | ROCK      |
| 2        | 3       | 1       | Fight Story             | 194      | ROCK      |
| 3        | 1       | 1       | Not About The Guitar    | 278      | BLUES     |
+----------+---------+---------+-------------------------+----------+-----------+
9 rows in set (5.48 msecs)

spanner> partitioned update Songs set SongName = "Foo Bar" WHERE SongGenre = 'ROCK';
Query OK, 3 rows affected (3.75 sec)

spanner> select * from Songs;
+----------+---------+---------+-------------------------+----------+-----------+
| SingerId | AlbumId | TrackId | SongName                | Duration | SongGenre |
+----------+---------+---------+-------------------------+----------+-----------+
| 2        | 1       | 1       | Let's Get Back Together | 182      | COUNTRY   |
| 2        | 1       | 2       | Foo Bar                 | 156      | ROCK      |
| 2        | 1       | 3       | I Knew You Were Magic   | 294      | BLUES     |
| 2        | 1       | 4       | 42                      | 185      | CLASSICAL |
| 2        | 1       | 5       | Blue                    | 238      | BLUES     |
| 2        | 1       | 6       | Nothing Is The Same     | 303      | BLUES     |
| 2        | 1       | 7       | Foo Bar                 | 255      | ROCK      |
| 2        | 3       | 1       | Foo Bar                 | 194      | ROCK      |
| 3        | 1       | 1       | Not About The Guitar    | 278      | BLUES     |
+----------+---------+---------+-------------------------+----------+-----------+
9 rows in set (51.09 msecs)

spanner> partitioned delete from Songs WHERE SongGenre = 'ROCK';
Query OK, 3 rows affected (3.30 sec)

spanner> select * from Songs;
+----------+---------+---------+-------------------------+----------+-----------+
| SingerId | AlbumId | TrackId | SongName                | Duration | SongGenre |
+----------+---------+---------+-------------------------+----------+-----------+
| 2        | 1       | 1       | Let's Get Back Together | 182      | COUNTRY   |
| 2        | 1       | 3       | I Knew You Were Magic   | 294      | BLUES     |
| 2        | 1       | 4       | 42                      | 185      | CLASSICAL |
| 2        | 1       | 5       | Blue                    | 238      | BLUES     |
| 2        | 1       | 6       | Nothing Is The Same     | 303      | BLUES     |
| 3        | 1       | 1       | Not About The Guitar    | 278      | BLUES     |
+----------+---------+---------+-------------------------+----------+-----------+
6 rows in set (6.84 msecs)

close: #93

[yfuruyama]

@apstndb Please review this PR when you have time. Thanks!

[apstndb]

It is a major update!

TRUNCATE TABLE can be an alias of PARTITIONED DELETE `tbl` WHERE TRUE in both of semantics and implementation.
The behavior will be clear, so why not make it an alias by the time you release it?

[apstndb]

👍

[yfuruyama]

TRUNCATE TABLE can be an alias of PARTITIONED DELETE tbl WHERE TRUE in both of semantics and implementation.
The behavior will be clear, so why not make it an alias by the time you release it?

Initially I implemented so, but I have found error messages (example) have to be different from Partitioned DML, so I kept the implementation of TRUNCATE TABLE as it is. Using Partitioned DML for TRUNCATE TABLE is part of implementation details and I think it should be hidden from users.

[apstndb]

OK, I understand the reason.
I agree it is an implementation detail.

Another choice:

• It is message only reason so switch message (e.g. by enum value in PartitionedDmlStatement)

[apstndb]

LGTM

[yfuruyama]

Thanks for reviewing!

It is message only reason so switch message (e.g. by enum value in PartitionedDmlStatement)

Yeah that's totally fine. Then let's change the implementation once we emulate other SQL functionalities with Partitioned DML 👍