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limitation noted: generated columns

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Shlomi Noach 2016-07-31 15:25:32 +02:00
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doc/requirements-and-limitations.md
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@ -12,7 +12,8 @@
### Limitations ### Limitations
- Foreign keys not supported. They may be supported in the future, to some extent. - Foreign keys not supported. They may be supported in the future, to some extent.
- Triggers are not supported. they may be supported in the future. - Triggers are not supported. They may be supported in the future.
- MySQL 5.7 generated columns are not supported. They may be supported in the future.
- The two _before_ & _after_ tables must share some `UNIQUE KEY`. Such key would be used by `gh-ost` to iterate the table. - The two _before_ & _after_ tables must share some `UNIQUE KEY`. Such key would be used by `gh-ost` to iterate the table.
- As an example, if your table has a single `UNIQUE KEY` and no `PRIMARY KEY`, and you wish to replace it with a `PRIMARY KEY`, you will need two migrations: one to add the `PRIMARY KEY` (this migration will use the existing `UNIQUE KEY`), another to drop the now redundant `UNIQUE KEY` (this migration will use the `PRIMARY KEY`). - As an example, if your table has a single `UNIQUE KEY` and no `PRIMARY KEY`, and you wish to replace it with a `PRIMARY KEY`, you will need two migrations: one to add the `PRIMARY KEY` (this migration will use the existing `UNIQUE KEY`), another to drop the now redundant `UNIQUE KEY` (this migration will use the `PRIMARY KEY`).
- The chosen migration key must not include columns with `NULL` values. - The chosen migration key must not include columns with `NULL` values.