Don't use schema cache when checking schema migrations #43877
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I noticed this while debugging a separate issue locally. When `lazily_load_schema_cache` is set to true AND there's a schema cache, running `db:drop` twice will raise a `no such table: schema_migrations` error. The problem here was that when `check_protected_environments` is run before drop, the task checks for the latest environment. That check looks at `table_exists?` defined in `model_schema.rb`. The issue is that the model schema is checking `connection.schema_cache.data_source_exists?`. When checking whether the environment is protected or schema migrations we don't want to use the schema cache. We want to check the database directly. The schema cache really is for the app after boot, so it's safe to skip the schema cache in this area since we want to check the database directly.
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Note to self: this needs a backport to 7-0-stable. |
eileencodes
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Dec 15, 2021
…chema-migrations Don't use schema cache when checking schema migrations
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Backported in 7d924ab |
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I noticed this while debugging a separate issue locally. When
lazily_load_schema_cacheis set to true AND there's a schema cache,running
db:droptwice will raise ano such table: schema_migrationserror. The problem here was that when
check_protected_environmentsisrun before drop, the task checks for the latest environment. That check
looks at
table_exists?defined inmodel_schema.rb. The issue is thatthe model schema is checking
connection.schema_cache.data_source_exists?.When checking whether the environment is protected on schema migrations
we don't want to use the schema cache. We want to check the database
directly. The schema cache really is for the app after boot, so it's
safe to skip the schema cache in this area since we want to check the
database directly.