.tip

Jul 10, 2026 · one of the small things

If the fix is 'wait', it should not page

An alert that clears itself before anyone could act on it trains on-call to ignore the pager. Wait it out with a for clause, and if it always clears within five minutes, make it a ticket instead of a page.

for: 10m

Page for things a human has to deal with in the next fifteen minutes. Everything else goes to a channel and gets looked at in the morning.

observabilitysre

~/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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