If you are using WSO2 Governance Registry or API Manager product, you might be already aware that all the registry related actions are being logged. This REG_LOG table being read for Solr indexing(store and publisher searching). Based on the REG_LOG table entries we are indexing artifact metadata. However, with the time this table size might grow. So as a maintain step you can clean up obsolete records from that table.
So you can use below query to delete obsolete records from REG_LOG table.
DELETE n1 FROM REG_LOG n1, REG_LOG n2 WHERE n1.REG_LOG_ID < n2.REG_LOG_ID AND n1.REG_PATH = n2.REG_PATH AND n1.REG_TENANT_ID = n2.REG_TENANT_ID;
DELETE FROM REG_LOG WHERE REG_ACTION = 7;