How to create dynamic partition table in postgres with bigint column? - sql

Question

I have a master table such as
CREATE TABLE public.user_event_firebase
(
user_id character varying(32) COLLATE pg_catalog."default" NOT NULL,
event_name character varying(255) COLLATE pg_catalog."default" NOT NULL,
"timestamp" bigint NOT NULL,
platform character varying(255) COLLATE pg_catalog."default" NOT NULL,
created_at timestamp without time zone DEFAULT now()
)
WITH (
OIDS = FALSE
)
TABLESPACE pg_default;
GOAL
I want to partition this table by year_month table with "timestamp" column such as user_event_firebase_2018_04 , user_event_firebase_2018_05, user_event_firebase_2018_06. The rows will automation redirect to insert into partition table with timestamp condition.
I created function create partition such as:
CREATE OR REPLACE FUNCTION partition_uef_table( bigint, bigint )
returns void AS $$
DECLARE
create_query text;
index_query text;
BEGIN
FOR create_query, index_query IN SELECT
'create table user_event_firebase_'
|| TO_CHAR( d, 'YYYY_MM' )
|| ' ( check( timestamp >= bigint '''
|| TO_CHAR( d, 'YYYY-MM-DD' )
|| ''' and timestamp < bigint '''
|| TO_CHAR( d + INTERVAL '1 month', 'YYYY-MM-DD' )
|| ''' ) ) inherits ( user_event_firebase );',
'create index user_event_firebase_'
|| TO_CHAR( d, 'YYYY_MM' )
|| '_time on user_event_firebase_'
|| TO_CHAR( d, 'YYYY_MM' )
|| ' ( timestamp );'
FROM generate_series( $1, $2, '1 month' ) AS d
LOOP
EXECUTE create_query;
EXECUTE index_query;
END LOOP;
END;
$$
language plpgsql;
CREATE OR REPLACE FUNCTION test_partition_function_uef()
RETURNS TRIGGER AS $$
BEGIN
EXECUTE 'insert into user_event_firebase_'
|| to_char( NEW.timestamp, 'YYYY_MM' )
|| ' values ( $1, $2, $3, $4 )' USING NEW.user_id, NEW.event_name, NEW.timestamp, NEW.platform;
RETURN NULL;
END;
$$
LANGUAGE plpgsql;
with trigger
CREATE TRIGGER test_partition_trigger_uef
BEFORE INSERT
ON user_event_firebase
FOR each ROW
EXECUTE PROCEDURE test_partition_function_uef() ;
I trying with example
SELECT partition_uef_table(1518164237,1520583437) ;
PROBLEM :
ERROR: invalid input syntax for integer: "1 month"
LINE 14: FROM generate_series( $1, $2, '1 month' ) AS d
^
QUERY: SELECT
'create table user_event_firebase_'
|| TO_CHAR( d, 'YYYY_MM' )
|| ' ( check( timestamp >= bigint '''
|| TO_CHAR( d, 'YYYY-MM-DD' )
|| ''' and timestamp < bigint '''
|| TO_CHAR( d + INTERVAL '1 month', 'YYYY-MM-DD' )
|| ''' ) ) inherits ( user_event_firebase );',
'create index user_event_firebase_'
QUESTION:
How to create range for generate_series function in ' 1 month ' , set step property such int or bigint suck because of day of month is diffirence ( 2nd - 28 days, 3rd - 30 days ).
Thank you.

Answer 1

answer to your second question would be opinion based (so I skip it), but to the first would be such:
with args(a1,a2) as (values(1518164237,1520583437))
select d,to_char(d,'YYYY_MM') from args, generate_series(to_timestamp(a1),to_timestamp(a2),'1 month'::interval) d;
gives reult:
d | to_char
------------------------+---------
2018-02-09 08:17:17+00 | 2018_02
2018-03-09 08:17:17+00 | 2018_03
(2 rows)
Use
generate_series(start, stop, step interval) timestamp or timestamp with time zone