Re: PostgreSQL add id column that increments based on data

Thank you for the input.

I have come up with the following solution:

CREATE TABLE data_raw (
raw_data TEXT
);

COPY data_raw FROM 'C:\path\data_x.txt' ...; -- Repeated for each file

ALTER TABLE data_raw
ADD COLUMN pk_id serial,
ADD COLUMN id integer,
ADD COLUMN indicator integer;

UPDATE data_raw SET
indicator = CAST(substr(raw_data, 1, 1) AS integer),
raw_data = substr(raw_data, 2);

CREATE TABLE id_base AS
SELECT
pk_id,
sum(CASE WHEN indicator = 1 THEN 1 ELSE 0 END) OVER (ORDER BY pk_id) AS
rec_id
FROM data_raw;

CREATE INDEX id_base_pk ON id_base USING btree(pk_id);

UPDATE data_raw r SET
id = (SELECT rec_id FROM id_base b WHERE b.pk_id = r.pk_id);

DROP TABLE id_base;

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