Postgres 15

By using db<>fiddle, you agree to license everything you submit by Creative Commons CC0.

Help with an interesting Postgres question: Why isn't an Index Only Scan used on a partition accessed via the parent table?.

select ARRAY(SELECT DISTINCT UNNEST(array_cat(null, ARRAY['hijk-23lm'])));

array

{hijk-23lm}

SELECT 1

select ARRAY(SELECT DISTINCT UNNEST(array_cat('{}', ARRAY['hijk-23lm'])));

array

{hijk-23lm}

SELECT 1

select ARRAY(SELECT DISTINCT UNNEST(array_cat('{null}', ARRAY['hijk-23lm'])));

array

{hijk-23lm,NULL}

SELECT 1

select ARRAY(SELECT DISTINCT UNNEST(array_cat('{null,null}', ARRAY['hijk-23lm'])));

array

{hijk-23lm,NULL}

SELECT 1

select array_cat(null::text[],'{a,b,c}'::text[]);

array_cat

{a,b,c}

SELECT 1

select array_cat('{}'::text[],'{a,b,c}'::text[]);

array_cat

{a,b,c}

SELECT 1

select array_append(null::text[],'a'::text);

array_append

{a}

SELECT 1

select array_append('{}'::text[],'a'::text);

array_append

{a}

SELECT 1

select array_cat('{a,b,c}'::text[],null::text[]);

array_cat

{a,b,c}

SELECT 1

select array_cat('{a,b,c}'::text[],'{}'::text[]);

array_cat

{a,b,c}

SELECT 1

select array_cat(null::text[],null::text[]);

array_cat

null

SELECT 1

select array_append('{a}'::text[],null);

array_append

{a,NULL}

SELECT 1

select ARRAY(SELECT DISTINCT UNNEST(array_cat(null::text[], ARRAY['hijk-23lm'] )));

array

{hijk-23lm}

SELECT 1

select ARRAY(SELECT DISTINCT UNNEST(array_cat('{}'::text[], ARRAY['hijk-23lm'] )));

array

{hijk-23lm}

SELECT 1