.tip

Feb 28, 2026 · one of the small things

range-diff shows what a rebase actually changed

After a force push, the reviewer wants to know "what changed since I looked". A normal diff between the two branch tips is useless, because the base moved. range-diff compares the two series commit by commit.

git range-diff main feat@{1} feat

It shows which commits are identical and which were reworded, and gives you the diff of the diff for the ones that changed.

gitcode-review

~/tips/today — 2026-10-19

~cat tips/today

Never build an index on a live table without CONCURRENTLY

postgresqlmigrations

A plain CREATE INDEX takes a lock that blocks every write to the table for the whole build. On a big table that means minutes of outage that look like a hung app.

CREATE INDEX CONCURRENTLY orders_customer_idx ON orders (customer_id);

It's slower and can't run inside a transaction, so you'll have to tell your migration tool. If it fails halfway, it leaves an invalid index behind, so check pg_index.indisvalid and drop it before you retry.

↵ open y yesterday l ls /tips

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