-
Notifications
You must be signed in to change notification settings - Fork 70
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
- Loading branch information
1 parent
fc49dfd
commit 7abefeb
Showing
1 changed file
with
1 addition
and
1 deletion.
There are no files selected for viewing
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
Original file line number | Diff line number | Diff line change |
---|---|---|
|
@@ -40,7 +40,7 @@ | |
|
||
![migration flow](img/[email protected]) | ||
|
||
During the migration start phase, `pgroll` will perform only additive changes to the database schema. This includes: creating new tables, adding new columns, and creating new indexes. In the cases were a required change is not backwards compatible, `pgroll` will take the necessary steps to ensure that the current schema is still valid. For example, if a new column is added to a table with a `NOT NULL` constraint, `pgroll` will backfill the new column with a default value. | ||
During the migration start phase, `pgroll` will perform only additive changes to the database schema. This includes: creating new tables, adding new columns, and creating new indexes. In the cases where a required change is not backwards compatible, `pgroll` will take the necessary steps to ensure that the current schema is still valid. For example, if a new column is added to a table with a `NOT NULL` constraint, `pgroll` will backfill the new column with a default value. | ||
|
||
After a successful migration start, the database will contain two versions of the schema: the old version and the new version. The old version of the schema is still available to client applications. This allows client applications to be updated to use the new version of the schema without any downtime. | ||
|
||
|