SQL

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19. (5 points) In general, on limited memory system, no indexes, and huge gener system, no indexes and huge tables, what join type would perform best? (a) merge join (b) hash join. (c) indexed lookup join. (d) inner loop join. (e) Other: 20. (5 points) Below query is identical to: select a. ,b.val from T1a left outer join T2 b on a.key-b.key and a.val!-b.val (a) with TMP as (select a.*,b.val from T1 a left outer join T2 b on a.key b.key where a.val!-b.val) select a.* from TMP where a.val! b.val (b) with TMP as (select a.*,b.val from T1 a inner join T2 b on a.key-b.key where a.val!-b.val) select a.*,b.val from T1 a left outer join TMP b on a.key-b.key (c) select a. *,b.val from T1 a inner join T2 b on a.key-b.key and a.val! b.val (d) All of the above queries are identical. (e) None of the queries are identical to the