== Summary
This task is to create a `gb_address` column in the `globalblocks` table
== Background
- We want to rename the `gb_address` column to `gb_target` to:
-- Fix the schema inconsistency between WMF production and the SQL files in the extension on `gb_address` (both having a default value and having a different data type), because from what I can tell it wouldn't likely be possible to just change the column type without also breaking existing data
-- Standardise the column name with `gb_target_central_id`, given that `gb_address` can now contain usernames (and not just IP addresses)
== Proposed schema changes
=== Stage 1: Create gb_target and add default to gb_address
Add the `gb_target` column to the `globalblocks` table which matches the definition of `gb_address` in the SQL files in the extension
```lang=sql
ALTER TABLE /*_*/globalblocks
ADD gb_target VARCHAR(255) NOT NULL;
```
Also add a default to the `gb_address` column, which should not need to be applied to WMF wikis as it already has a default of an empty string
=== Step 2: Drop gb_address
Once appropriately migrated to use the `gb_target` column everywhere, the old `gb_address` column can be dropped from both WMF production and the extension SQL files
```lang=sql
ALTER TABLE /*_*/globalblocks
DROP gb_address;
```
== Acceptance criteria
* [ ] The first schema change is applied to the master branch of #globalblocking
* [ ] A #schema-change-in-production ticket is filed to create the `gb_target` column
* [ ] Tickets are filed to track future of the schema changes once given a green light by DBAs