{"image_url":null,"version":"1.0","author_name":"shigemk2","url":"https://www.shigemk2.com/entry/2017/07/31/presto_cardinality_map","html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Fwww.shigemk2.com%2Fentry%2F2017%2F07%2F31%2Fpresto_cardinality_map\" title=\"presto cardinality map - by shigemk2\" class=\"embed-card embed-blogcard\" scrolling=\"no\" frameborder=\"0\" style=\"display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;\"></iframe>","provider_url":"https://hatena.blog","author_url":"https://blog.hatena.ne.jp/shigemk2/","blog_title":"by shigemk2","categories":["Presto"],"width":"100%","title":"presto cardinality map","provider_name":"Hatena Blog","type":"rich","height":"190","description":"presto\u306ecardinality\u306fmap\u306esize\u3092\u8fd4\u3059\u3002map\u306f\u2193\u306e\u3088\u3046\u306a\u69cb\u9020\u3002 presto> select cardinality(map(ARRAY[1,2,3,4,5],ARRAY[3,4,4,5,6])); _col0 ------- 5 (1 row) presto> select map(ARRAY[1,2,3,4,5],ARRAY[3,4,4,5,6]); _col0 --------------------------- {1=3, 2=4, 3=4, 4=5, 5=6} (1 row) https://prestodb.io/docs/current/function\u2026","blog_url":"https://www.shigemk2.com/","published":"2017-07-31 12:46:36"}