På onsdag 25. januar 2017 kl. 09:47:56, skrev Thomas Kellerer <spam_eater@xxxxxxx>:
Alex Magnum schrieb am 25.01.2017 um 09:29:
> I can search an array with 1 = ANY('{1,3,4,7}'::int[])
>
> I need to check for one or multiple items in the array.
>
> e.g.'1,7,3' = ANY('{1,3,4,7}'::int[]
>
> I do need to check if
> a) all items exist in the array
You can use the contains (or is contained) operator for that:
array[1,7,3] <@ array[1,3,4,7] is true
array[1,7,10] <@ array[1,3,4,7] is false
> b) at least one item exists in the array
You can use the "overlaps" operator:
array[1,7,3] && array[1,3,4,7] returns true
array[10,11] && array[1,3,4,7] returns false
> Does the order of left and right side matter?
For the contains or (is contained) operator the order matters, for the overlaps operator it does not.
For more details see https://www.postgresql.org/docs/current/static/functions-array.html
Thomas
Can you elaborate on index-usage? Ie. will the suggested queries above utilize idexes (gist?). If so, can you give an example with definition of index and explain-plan?
It would be interesting to see how this performs vs. contrib/intarray.
Thanks.
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