Sort file name by number of changes in git history

git log --pretty=format: --name-only | sort | uniq -c | sort -rg | less

Literally copied from the answer of "Finding most changed files in git"

[PostgreSQL] Using some indexes from Composite index

If we had a composite index on three fields: we would be able to use it for queries on the first field, for queries on the first two fields and for queries involving all three fields, but not on any other field combination.

Copied directly from How to stop worrying and love your Postgres indexes