Confluence A0_54C900_C-TEMPLATE_REF Table Millions Entries

Hi!

Confluence 7.4.0.

We realized, that the mentioned DB-Table has millions of entries which seem to be related to the Space-Blueprint Definitions within atlassian-plugin.xml.

We are trying to upgrade the System, but the big table somehow slows everything down and we are not sure, if the upgrade suceeds.

Is it safe to delete the entries within this table or would it have an effect on our already existing spaces ?

Any hints on how to handle this would be greatly appreciated!

Regards,
Hans