Here's an example:
```
wikiadmin@10.64.32.198(fawiki)> show index from ipblocks;
+----------+------------+---------------------+--------------+---------------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment |
+----------+------------+---------------------+--------------+---------------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| ipblocks | 0 | PRIMARY | 1 | ipb_id | A | 19209 | NULL | NULL | | BTREE | | |
| ipblocks | 0 | ipb_address_unique | 1 | ipb_address | A | 19209 | 255 | NULL | | BTREE | | |
| ipblocks | 0 | ipb_address_unique | 2 | ipb_user | A | 19209 | NULL | NULL | | BTREE | | |
| ipblocks | 0 | ipb_address_unique | 3 | ipb_auto | A | 19209 | NULL | NULL | | BTREE | | |
| ipblocks | 1 | ipb_user | 1 | ipb_user | A | 19209 | NULL | NULL | | BTREE | | |
| ipblocks | 1 | ipb_timestamp | 1 | ipb_timestamp | A | 19209 | NULL | NULL | | BTREE | | |
| ipblocks | 1 | ipb_expiry | 1 | ipb_expiry | A | 9604 | NULL | NULL | | BTREE | | |
| ipblocks | 1 | ipb_range | 1 | ipb_range_start | A | 19209 | 20 | NULL | | BTREE | | |
| ipblocks | 1 | ipb_range | 2 | ipb_range_end | A | 19209 | 20 | NULL | | BTREE | | |
| ipblocks | 1 | ipb_parent_block_id | 1 | ipb_parent_block_id | A | 20 | NULL | NULL | YES | BTREE | | |
+----------+------------+---------------------+--------------+---------------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
10 rows in set (0.00 sec)
```
But as of now, the ipb_address_unique has four columns tables.sql in core (HEAD of master) and the fourth one is missing:
```lang=sql
CREATE UNIQUE INDEX /*i*/ipb_address_unique ON /*_*/ipblocks (ipb_address(255), ipb_user, ipb_auto, ipb_anon_only);
```
I guess the alter table would be something like this:
```lang=sql
ALTER TABLE /*_*/ipblocks DROP INDEX IF EXISTS /*i*/ipb_address_unique; ALTER TABLE ipblocks ADD UNIQUE INDEX IF NOT EXISTS /*i*/ipb_address_unique (ipb_address(255), ipb_user, ipb_auto, ipb_anon_only);
```
Progress
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[x] s8
** [x] eqiad
** [x] codfw
[x] wikitech
** [x] labswiki
** [x] labtestwiki