with the following view:

CREATE OR REPLACE VIEW {accountId}.last_assets AS
SELECT DISTINCT ON (coin) * from {accountId}.{tableAssetsName} ORDER BY ts DESC LIMIT 1;

I want to get the latest of all rows with different 'coin' values. In short, the latest update of each coin.

Should I index (ts) and (coin) separately ? or should I index together (ts, coin)? (and why?)

CodePudding user response：

You could use an index on (coin, ts) in this order.

It is not guaranteed that PostgreSQL will use it, but it is the best index for the query.