Reduce CPU utilization of row count query
Previously, scraping the /database metrics used a significant amount of CPU because each query would rebuild the PG to Ruby data type map. We now memoize this map so we only need to build this map once.
Before (1.8 s)
After (0.07 s)
Closes https://gitlab.com/gitlab-org/gitlab-exporter/-/issues/75
Edited by Stan Hu