This attempts to add a README.md to help create consistent migrations
that maximize our test coverage and do not include unnecessary
statements.
It also adds a feature to have an `-- OLD DATA --` section as well
as a `-- NEW DATA --` section so that we can fix mistakes made in
previous snapshots (like a row that was forgotten to be added when a
table was created) without editing them going forward.
Change-Id: I28a786f8ef163cae1de1bb08f61af1e1104b0a88
Replace all the remaining uses of sql.DB with tagsql.DB to
fix issues with context cancellation.
Introduce tagsql.Open which helps to get rid of all tagsql.Wrap-s.
Use tagsql in cockroachkv and postgreskv.
Change-Id: I8946d203341cb85a25976896fc7881e1f704e779
dbschema.Query is used only for testing and sqlite,
so this won't cause us problems in production.
Change-Id: Ib296a7daf161a9d3de23a7dfdc4f505d47ac4a37
