Separate DDL operations from DML (backfills) on migration start #289
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Return the table that needs backfill, if any.
Collect all the tables that require backfill and backfill them once the DDL operations on `Start` have completed.
exekias
reviewed
Feb 28, 2024
exekias
reviewed
Feb 28, 2024
exekias
reviewed
Feb 28, 2024
exekias
approved these changes
Feb 28, 2024
andrew-farries
added a commit
that referenced
this pull request
Mar 1, 2024
…column in a backfill. (#298) Add a test to ensure that new columns can't be used as the identity for a backfill, even if they satisfy the conditions for an identity column. A newly added `NOT NULL` and `UNIQUE` column could in theory be used as the identity column for a backfill. However, it shouldn't be used as the identity column fora backfill because it's a newly added column whose temporary column will be full of NULLs for any existing rows in the table. Currently the column won't be selected as an identity for backfills because the nullability and uniqueness for new column are not populated when adding it to the virtual schema in the add_column operation: https://github.com/xataio/pgroll/blob/c08ef7065cdbce965110e64f58e66eddf605eaee/pkg/migrations/op_add_column.go#L61-L63 Following on from the discussion here: #289 (comment)
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Separate the DDL operations required during migration start from the DML operations (backfills). Complete all DDL steps before starting DML.
Each
Startoperation returns the name of the table that requires backfill, if any. After all operations have started, backfills are run on each table that requires one.Separating DDL and DML during migration start like this will allow for setting Postgres options that should apply only for the DDL phase of migration start (as in #290).