SQL/MX 3.2 Query Guide (H06.25+, J06.14+)

Compiling and Executing a Query
HP NonStop SQL/MX Release 3.2 Query Guide—663851-002
1-15
Improving Query Performance
>>INSERT INTO STAFF_UC VALUES (_ucs2'E1', N'Alice');
--- 1 row(s) inserted.
>>INSERT INTO WORKS_UC VALUES (_ucs2'E1', _ucs2'P3');
--- 1 row(s) inserted.
>>INSERT INTO PROJ_UC VALUES (_ucs2'P3', _ucs2'Tampa');
--- 1 row(s) inserted.
>>INSERT INTO PROJ_UC VALUES
(_ucs2 X'4E7A', _ucs2 X'4E2D56FD53174EAC');
--- 1 row(s) inserted.
>>
>>CONTROL QUERY SHAPE HASH_JOIN (CUT, HASH_JOIN (CUT, CUT));
--- SQL operation complete.
>>PREPARE xx FROM
SELECT STAFF_UC.EMPNAME
FROM STAFF_UC
WHERE STAFF_UC.EMPNUM IN
(SELECT WORKS_UC.EMPNUM
FROM WORKS_UC
WHERE WORKS_UC.PNUM IN
(SELECT PROJ_UC.PNUM
FROM PROJ_UC
WHERE
(
PROJ_UC.PNUM < _UCS2 X'00FF'
AND
TRANSLATE (PROJ_UC.CITY USING
UCS2TOISO88591) = 'Tampa'
)
OR
PROJ_UC.CITY = _UCS2 X'5929 6D25'
)
);
--- SQL command prepared.
>>
>>EXECUTE xx;
EMPNAME
-----------------------------------------------------
Alice
--- 1 row(s) selected.
>>
>>CONTROL QUERY SHAPE
MERGE_JOIN (
NESTED_JOIN (CUT, CUT, INDEXJOIN),
NESTED_JOIN (CUT, CUT)
);
--- SQL operation complete.
>>PREPARE yy FROM
SELECT STAFF_UC.EMPNAME
TP663851.fm Page 15 Thursday, August 2, 2012 4:47 PM