Oracle baza i Oracle Enterprise Manager Database Express 12c

Oracle Enterprise Manager Database Express 12c služi za praćenje stanja u bazi, kao i praćenje raznih SQL komandi nad samom bazom.
Kada se gledaju SQL akcije nad bazom (pod stavkom “Performance Hub/Monitored SQL”), one su u ovakvoj tabeli :

Evo objašnjenja pojedinačnih polja :
Status – Upit je završen, upit je u toku (vrti se krugić), upit završen greškom (crveni krstić)
Duration – vreme koje protekne za korisnika dok on ne dobije rezultat upita (znači najvažniji parametar :-))
Type – SQL, PL/SQL, DBOP (DataBase operation)
ID – unique identifier for the SQL statement
SQL Plan Hash –
User – ko je pokrenuo SQL komandu
Parallel – (DOP : degree of parallelism), parallel execution uses multiple processes to
accomplish a single task by splitting a task into smaller sub tasks (link)
Database Time – DB time is total time spent by user processes either actively working or actively waiting in a database call :
DB Time = CPU time + I/O time + Non-idle wait time
I/O requests – mere se po sekundi
Start – kad je startovana SQL komanda
Ended – kad se završila SQL komanda (prazno, ako se komanda još uvek izvršava)
SQL Text – sama SQL komanda
*****
SQL statements are monitored only if they have consumed at least 5 seconds of CPU or I/O time.
Most systems are performing satisfactorily if latency is fewer than 10 milliseconds.
*****
Dobar link.
Odličan PDF dokument.