Querying v_catalog.comments is very slow even with no results
When I query v_catalog.comments it takes well over a minute:
SELECT * FROM v_catalog.comments LIMIT 1;
Here are the results in DBeaver:
There is only one result returned, and that's because I explicitly added a comment to one table to test this query. Other than that one comment, no results are returned. It shouldn't be this slow. Other queries on this cluster seem to run fine.
I can't find much information on this comments table in Vertica documentation or in the Vertica database catalog itself. There is an entry for the comments table in all_tables but nowhere else. I can't tell if this is some kind of special table that is somehow backed by some unknown process that is in great need of optimization.
I don't care much about comments, but the problem is that DBeaver tries to gather object metadata for various user actions, and these queries seem to always involve the comments table. Any time you have auto-completion enabled, or when you expand nodes in the Database Manager pane, it tries to issue queries to Vertica to get information about the objects. This is especially true for any action that displays column information, like when you expand a table node, or double-click on a table. DBeaver is our company's main way of interacting with Vertica manually. I've tried to disable some of the metadata queries issued by DBeaver, but there are still many cases where the slowness of the comments table gets in the way. If you do the wrong thing, you have to wait a long minute for the GUI to update. As soon as the query involving the comments table finishes, the GUI then updates and you can continue working.
Our Vertica cluster is version 9.2.0-4.