SQL/MX 2.x Query Guide (G06.24+, H06.03+)

Reviewing Query Execution Plans

HP NonStop SQL/MX Query Guide—523728-003

4-21

Simple Query Example

This query selects all rows and columns from the EMPLOYEE table:

>>prepare q1 from

+>select * from employee;

--- SQL command prepared.

>>execute Q1;

The query returns this result:

EMPNUM FIRST_NAME LAST_NAME DEPTNUM JOBCODE SALARY

------ ----------- ---------- ------- -------- ------

1 ROGER GREEN 9000 100 175500.00

. . . . .

568 JESSICA CRINER 3500 300 39500.00

--- 62 row(s) selected.

To obtain statistics about the query, after the query executes, enter:

>>DISPLAY STATISTICS;

The statistics are returned:

Start Time 2005/05/06 10:45:53.916

End Time 2005/05/06 10:45:53.975

Elapsed Time 00:00:00.059

Compile Time 00:00:00.000

Execution Time 00:00:00.059

Table Name Records Records Disk Message Message Lock

Accessed Used I/Os Count Bytes

SAMDBCAT.PERSNL.EMPLOYEE

62 62 2 2 14608 0

If you want to display statistics automatically, enter SET STATISTICS ON at any point

during the session. As a result, the statistics appear immediately after each command

executes.

Using Measure

Use the Measure product to gather statistics on an SQL/MX database and application

programs. The Measure product provides statistics on process execution (SQLPROC)

and on individual statement execution (SQLSTMT). For information on using Measure

with SQL/MX, see the SQL/MX Installation and Management Guide. For information

about the Measure product, see the Measure Reference Manual.

Process Execution (SQLPROC)

For each process, the Measure product provides these statistics: