I've added the account_id filter to the
`get_agent_ids_over_assignment_limit` method. This optimization will
help the query leverage the existing composite index
`conv_acid_inbid_stat_asgnid_idx (account_id, inbox_id, status,
assignee_id)` for better performance.
**Before:**
```sql
HashAggregate (cost=224238.12..224256.27 rows=484 width=4)
Group Key: assignee_id
Filter: (count(*) >= 10)
-> Index Scan using index_conversations_on_inbox_id on conversations (cost=0.44..223963.67 rows=54891 width=4)
Index Cond: (inbox_id = ???)
Filter: (status = 0)
```
**After:**
```sql
GroupAggregate (cost=0.44..5688.30 rows=476 width=4)
Group Key: assignee_id
Filter: (count(*) >= 10)
-> Index Only Scan using conv_acid_inbid_stat_asgnid_idx on conversations (cost=0.44..5640.81 rows=5928 width=4)
Index Cond: ((account_id = ??) AND (inbox_id = ??) AND (status = 0))
```
16b98b6017