Which two are true about queries using set operators (UNION, UNION ALL, INTERSECT and MINUS)? (Choose two.)
Which two are true about queries using set operators (UNION, UNION ALL, INTERSECT and MINUS)? (Choose two.)
The queries using set operators (UNION, UNION ALL, INTERSECT, and MINUS) need to have an equal number of columns in each SELECT list to ensure that the result can be properly combined or compared across different sets. Additionally, the FOR UPDATE clause cannot be specified with these set operators since FOR UPDATE is used to lock rows and set operators are meant for combining or comparing result sets, which makes them incompatible.
Set operations cannot be performed on BLOB, CLOB, BFILE, VARRAY, or nested table columns. BCE is the Answer
Union all works with clob.
B,C & E All correct
BCE it is for sure
BCE per link.
CE is the answer None of the set operator can be used with CLOB -False The set operator which is excluding duplicate rows (intersect,minus,union) will fail to compare the LOB data type. Union all operator doesn't throw any error if it contains LOB datatype
The docu states: "The set operators are not valid on columns of type BLOB, CLOB, BFILE, VARRAY, or nested table."
Should be C and E. Tried it out !
Checking provided link, valid are BCE
Union All can use with BLOB. checked
https://docs.oracle.com/database/121/SQLRF/queries004.htm#SQLRF52341
B should be included into the TRUE answer: https://docs.oracle.com/en/database/oracle/oracle-database/19/sqlrf/The-UNION-ALL-INTERSECT-MINUS-Operators.html#GUID-B64FE747-586E-4513-945F-80CB197125EE The set operators are subject to the following restrictions: The set operators are not valid on columns of type BLOB, CLOB, BFILE, VARRAY, or nested table. The UNION, INTERSECT, and MINUS operators are not valid on LONG columns. If the select list preceding the set operator contains an expression, then you must provide a column alias for the expression in order to refer to it in the order_by_clause. You cannot also specify the for_update_clause with the set operators. You cannot specify the order_by_clause in the subquery of these operators. You cannot use these operators in SELECT statements containing TABLE collection expressions.
B: this option is wrong. we can use UNION ALL with 2 tables having columns with CLOB datatype. But we cannot use UNION,INTERSECT and MINUS SET operators as it performs removal of duplicate and sorting implicitly and could not work with CLOB.
Hi, but in official doc from oracle, i found: The set operators are subject to the following restrictions: The set operators are not valid on columns of type BLOB, CLOB, BFILE, VARRAY, or nested table. The UNION, INTERSECT, EXCEPT, and MINUS operators are not valid on LONG columns. If the select list preceding the set operator contains an expression, then you must provide a column alias for the expression in order to refer to it in the order_by_clause. You cannot also specify the for_update_clause with the set operators. You cannot specify the order_by_clause in the subquery of these operators. You cannot use these operators in SELECT statements containing TABLE collection expressions.
CB The set operators are not valid on columns of type BLOB, CLOB, BFILE, VARRAY, or nested table. https://docs.oracle.com/en/database/oracle/oracle-database/19/sqlrf/The-UNION-ALL-INTERSECT-MINUS-Operators.html#GUID-B64FE747-586E-4513-945F-80CB197125EE