Re: How to append an element to a row inside a 2-dim. array?

... and I'm wondering if an index really speeds up array functions:
CREATE INDEX idx_ourarrtable_arr ON ourarrtable USING GIN(arr);

Stefan

2013/3/11 Stefan Keller <sfkeller(at)gmail(dot)com>:
> Hi,
>
> Question regarding arrays: How can I append an element to a row inside
> a 2-dim. array?
> See example below.
> And:
> Does anybody have experiences how arrays perform if data grows (it's
> "read-mostly")?
>
> Yours, Stefan
>
> --
> -- Arrays Test
> --
>
> CREATE TABLE ourarrtable (id int primary key, arr int[]);
>
> INSERT INTO ourarrtable VALUES (1, '{1,2,3}');
> INSERT INTO ourarrtable VALUES (2, '{{11,12,13},{21,22,23},{31,32,33}}');
>
> SELECT * FROM ourarrtable ORDER BY id;
> /*
> 1;"{1,2,3}"
> 2;"{{11,12,13},{21,22,23},{31,32,33}}"
> */
> SELECT arr[1:1] FROM ourarrtable WHERE id=2;
> -- "{{11,12,13}}"
>
> -- Works for 1-dim. array in row 1:
> UPDATE ourarrtable SET arr = array_append(arr, 4) WHERE id = 1;
>
> -- How to append say number 14 to '{11,12,13}' inside 2-dim. array?
> UPDATE ourarrtable SET arr[1:1] = array_cat(arr[1:1], 14) WHERE id = 1;
> /*
> ERROR: Function array_cat(integer[], integer) does not exist
> LINE 1: UPDATE ourarrtable SET arr[1:1] = array_cat(arr[1:1], 14) WH...
> */