Check if records exists in a Postgres table

Question

I have to read a CSV every 20 seconds. Each CSV contains min. of 500 to max. 60000 lines. I have to insert the data in a Postgres table, but before that I need to check if t

Answer 1

This should perform well:

CREATE TEMP TABLE tmp AS SELECT * FROM tbl LIMIT 0 -- copy layout, but no data

COPY tmp FROM '/absolute/path/to/file' FORMAT csv;

INSERT INTO tbl
SELECT tmp.*
FROM   tmp
LEFT   JOIN tbl USING (tbl_id)
WHERE  tbl.tbl_id IS NULL;

DROP TABLE tmp; -- else dropped at end of session automatically

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