Every 5 minutes, there are two queries that are executing on my cluster (apparently by MemSQL – not by any of our applications):
SELECT DATABASE_NAME, TABLE_NAME, COLUMN_NAME, SUM(COMPRESSED_SIZE) AS comp_size, SUM(UNCOMPRESSED_SIZE) AS uncomp_size FROM information_schema.COLUMNAR_SEGMENTS GROUP BY DATABASE_NAME, TABLE_NAME, COLUMN_NAME;
SELECT IFNULL(SUM(COMPRESSED_SIZE), 0) AS diskUsage FROM INFORMATION_SCHEMA.COLUMNAR_SEGMENTS;
When these queries run, they take 1m+ to run and cause the CPU on all leaf nodes to spike to close to 100% Admittedly I have many large columnstore tables currently being stored in the cluster, but they’re not actively being written to or read from. Is there any way to reduce the impact of these queries on the cluster?
I’m currently running MemSQL 6.5.8.