2
votes
1answer
144 views

Query results in a strange explain output

So I have a medium sized query that hits 15 tables. The query takes 36 sec on MySQL to complete. I ran EXPLAIN on the query and one of the tables returned this. '1', 'SIMPLE', 'mount_adapters', ...
5
votes
1answer
731 views

Oracle concatenation of queries and function index usage

I have a problem with something I can't understand about indexes in Oracle 11g. We can create test data with: create table test2(field1 varchar2(100),field2 varchar2(100),field3 number,field4 ...