Some Oracle Query Optimization Tips
Tip 1: Using REGEXP_LIKE (Oracle 11g+) Worse: select * from table where a like '%x%' or a like '%y%' or a like '%z%'; Better: select * from table where regexp_like('x|y|z'); Tip 2: Generating Multiple Columns Worse: select 'abc' from dual union all select 'bcd' from dual union all select 'xyz' from dual; Better: select column_value from table(sys.odcivarchar2tolist('abc','bcd','xyz'));