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| author | Valery Sizov <valery@gitlab.com> | 2017-05-18 11:35:59 +0300 |
|---|---|---|
| committer | Valery Sizov <valery@gitlab.com> | 2017-05-18 11:35:59 +0300 |
| commit | cf9d9d865daee2f3c0dd549afa3b168a8e1e679e (patch) | |
| tree | 77eb3bee305a9abca3ef92c457959e5ac2079794 | |
| parent | a49337727be1e28c29ad19b310fa2eb2df828c91 (diff) | |
| download | gitlab-ce-change_migration_style_guide.tar.gz | |
[Migration guide] Add note about prefering change_column_null over change_columnchange_migration_style_guide
| -rw-r--r-- | doc/development/what_requires_downtime.md | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/doc/development/what_requires_downtime.md b/doc/development/what_requires_downtime.md index 8da6ad684f5..c4830322fa8 100644 --- a/doc/development/what_requires_downtime.md +++ b/doc/development/what_requires_downtime.md @@ -139,6 +139,8 @@ Adding or removing a NOT NULL clause (or another constraint) can typically be done without requiring downtime. However, this does require that any application changes are deployed _first_. Thus, changing the constraints of a column should happen in a post-deployment migration. +NOTE: Avoid using `change_column` as it produces inefficient query because it re-defines +the whole column type. For example, to add a NOT NULL constraint, prefer `change_column_null ` ## Changing Column Types |