<table>civicrm_contact</table>
<key>id</key>
<add>1.6</add>
+ <drop>5.31</drop>
<onDelete>CASCADE</onDelete>
</foreignKey>
+ <index>
+ <name>index_contact_id</name>
+ <fieldName>contact_id</fieldName>
+ <add>5.31</add>
+ </index>
<field>
<name>acl_id</name>
<title>Cache ACL</title>