CODEWITHSUNDEEP
google-cloud-spanner
Greg Hilston
Greg Hilston

Reputation: 2424

Does INTERLEAVE support the transitive property?

Lets say I have three tables, Foo, Bar and Baz

CREATE TABLE Foo (
FooId BYTES(MAX)
) PRIMARY KEY (FooId);

CREATE TABLE Bar (
FooId BYTES(MAX),
BarId BYTES(MAX)
) PRIMARY KEY (FooId, BarId),
INTERLEAVE IN PARENT Foo on DELETE CASCADE;

CREATE TABLE Baz (
FooId BYTES(MAX),
BazId BYTES(MAX)
) PRIMARY KEY (FooId, BazId),
INTERLEAVE IN PARENT Foo on DELETE CASCADE;

This diagram demonstrates the INTERLEAVE hierarchy:

+-----+   +-----+
|     |   |     |
| Foo <---+ Bar |
|     |   |     |
+--^--+   +-----+
   |
+--+--+
|     |
| Baz |
|     |
+-----+

Cloud Spanner's documentation Describes INTERLEAVE as

You can define hierarchies of parent-child relationships between tables up to seven layers deep, which means you can co-locate rows of seven logically independent tables.

Since we used INTERLEAVE between Bar and Foo, I believe we're guaranteed that they are co-located, with the same keys. Just like how we INTERLEAVE Baz and Bar, they should be co-located as well, with the same keys.

If that's true, then are we guaranteed that Bar and Baz are co-located, with the same keys, as well?

Upvotes: 3

Views: 80

Answers (1)

yongchul
yongchul

Reputation: 371

In the scenario described, Bar and Baz are collocated (or in the same split) given a FooId key. Within a split, the rows from each table are grouped together.

Upvotes: 2

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