PGCES-02 試験問題を無料オンラインアクセス

The table "foo" is defined as follows:
CREATE TABLE foo (bar TEXT);
Next, four SQL statements were executed in the following order. INSERT INTO foo VALUES
('bar'); -------- (1)
ALTER TABLE foo ADD COLUMN c1 TEXT; ---- (2)
ALTER TABLE foo ADD UNIQUE (c1); ------- (3)
ALTER TABLE foo DROP COLUMN bar; ------- (4)
Select the correct statement from those below.

• A.An error occurs when executing the (4) SQL statement.
• B.An error occurs when executing the (3) SQL statement.
• C.An error occurs when executing the (2) SQL statement.
• D.An error occurs when executing the (1) SQL statement.
• E.No error is generated.

The "sample" table consists of the following data:
How many rows are returned by executing the following SQL statement? SELECT * FROM
sample WHERE v ~ 'ab';

• A.3 rows
• B.0 rows
• C.4 rows
• D.1 row
• E.2 rows

Select one incorrect statement concerning the relational data model.

• A.It is a model based on set theory.
• B.It is a model that was proposed by F. Codd in 1970.
• C.It is made up of a multiple stage hierarchy where each of the set elements has parent child relationships.
• D.It expresses the real world in a collection of 2-dimensional tables called a relation.
• E.It has a logical structure independent of physical data structure.

You want to create a cursor that will SELECT the "customer" table. The created cursor must be able to move in any direction and reference data even after the end of the transaction.
Select one answer containing the correct keyword(s) to fill in the underlined blank below.
DECLARE cursor1 __________ FOR SELECT * FROM customer;

• A.CURSOR
• B.NO SCROLL CURSOR WITH HOLD
• C.CURSOR WITHOUT HOLD
• D.INSENSITIVE CURSOR
• E.SCROLL CURSOR WITH HOLD

Select two correct statements from below concerning the ANALYZE command.

• A.It takes some time to execute, but it does not lock the table.
• B.If the FULL option is used when executing, the size of the file can be reduced.
• C.It renews the statistical information of the table content.
• D.If ANALYZE is not used atall, there are times when it becomes impossible to see any of the data.
• E.If ANALYZE isinsufficient, the most efficient search plan will not be selected for queries.