> its been years and google and has been building out various pieces of infrastructure around mysql - including cloud spanner.
What does Cloud Spanner have to do with MySQL? It's neither API nor SQL-dialect compatible with MySQL. If there are MySQL bits used somewhere in the implementation, they are well hidden, and irrelevant to users.
> the issue is that the migration path of self hosted mysql to cloud sql to spanner is pretty well defined.
So what? Were there a Cloud SQL-like Postgres offering, the same would be true; Spanner is no closer to MySQL than Postgres. (If anything, it's SQL dialect is a little closer to Postgres's dialect than MySQL's, though not so much that you'll get away without doing substantial conversion going from either.)
What does Cloud Spanner have to do with MySQL? It's neither API nor SQL-dialect compatible with MySQL. If there are MySQL bits used somewhere in the implementation, they are well hidden, and irrelevant to users.
> the issue is that the migration path of self hosted mysql to cloud sql to spanner is pretty well defined.
So what? Were there a Cloud SQL-like Postgres offering, the same would be true; Spanner is no closer to MySQL than Postgres. (If anything, it's SQL dialect is a little closer to Postgres's dialect than MySQL's, though not so much that you'll get away without doing substantial conversion going from either.)