civicrm_group is missing important indexes on cache fields
We had a recent server degradation where queries ran a lot slower and I spotted a non-indexed query that the small table size would normally cause to fly under the radar - basically we need to add these indexes:
$tables = ['civicrm_group' => ['cache_date', 'refresh_date']];
CRM_Core_BAO_SchemaHandler::createIndexes($tables);
Note I'm just logging, rather than doing a PR, at this stage as I'm pretty snowed under.
@seamuslee @mattwire FYI - you might get benefit from indexing this