Oracle MySQL 8.0 Database Developer - 1z1-909 Free Exam Questions

A. A table can have multiple AUTO_INCREMENT columns.

B. AUTO_INCREMENT values allocated to a transaction that is rolled back are not reused.

C. A server restart always resets the AUTO_INCREMENT value to largest value in the AUTO_INCREMENT column plus 1.

D. An AUTO_INCREMENT column must be indexed.

E. The decimal data type supports AUTO_INCREMENT.

A. No transaction commits.

B. Two transactions commit.

C. No row is inserted into band.

D. The transaction is rolled back to the savepoint.

E. One row is inserted into band.

A. Execution performance can be improved by using like instead of RLIKE.

B. Execution performance can be improved by adding an index on column description.

C. The statement takes advantage of index description_idx.

D. No index will improve statement performance.

E. Execution performance can be improved by, using a composite index with column description as the leftmost prefix column description.

A. The json_extract() function requires a length value that matches the field length in the schema.

B. The select requires json_unquoteo in the where clause.

C. The virtual values in the name column must be accessed using functions.

D. The JSON datatype cannot be used in virtual columns.

E. Table statistics must be updated to generate values for the name column.

A. SELECT name FROM col WHERE season = 1;

B. SELECT doc->,,$.name,, FROM col WHERE doc->"$ . season" = "1";

C. SELECT doc->"$.name" FROM col WHERE doc->"$.season" = "1";

D. SELECT "S.name" FROM col WHERE "S.season" = "1";

A. Secondary index access will always be faster than a table scan.

B. Indexes are used to enforce unique constraints.

C. Indexes reduce disk space used.

D. Indexing all of a table's columns improves performance.

E. Indexes contain rows sorted by key values.

A.

B.

C.

D.

E.