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Diffstat (limited to 'doc/development/migration_style_guide.md')
| -rw-r--r-- | doc/development/migration_style_guide.md | 7 |
1 files changed, 1 insertions, 6 deletions
diff --git a/doc/development/migration_style_guide.md b/doc/development/migration_style_guide.md index 6f31e5b82e5..e4e532bb4ed 100644 --- a/doc/development/migration_style_guide.md +++ b/doc/development/migration_style_guide.md @@ -187,12 +187,7 @@ end When adding a foreign-key constraint to either an existing or new column remember to also add a index on the column. -This is _required_ if the foreign-key constraint specifies -`ON DELETE CASCADE` or `ON DELETE SET NULL` behavior. On a cascading -delete, the [corresponding record needs to be retrieved using an -index](https://www.cybertec-postgresql.com/en/postgresql-indexes-and-foreign-keys/) -(otherwise, we'd need to scan the whole table) for subsequent update or -deletion. +This is _required_ for all foreign-keys. Here's an example where we add a new column with a foreign key constraint. Note it includes `index: true` to create an index for it. |