LAST_QUERY_COST (Oracle)

LAST_QUERY_COST (Oracle) is a SQL statement in the Oracle Specific category. Oracle: dynamic performance views (V$ views) for monitoring SQL execution, performance, and resource usage. The syntax is SELECT * FROM V$SQL WHERE SQL_TEXT LIKE '%query_part%';. It returns performance views data. A typical example: -- Find expensive queries: SELECT sql_id, sql_text, elapsed_time/1000000 AS elapsed_sec, cpu_time/1000000 AS cpu_sec, buffer_gets, disk_reads, executions FROM v$sql ORDER BY elapsed_time DESC FETCH FIRST 10 ROWS ONLY; -- Current session info: SELECT sid, serial#, username, status, osuser, machine, program FROM v$session WHERE username IS NOT NULL; -- SQL Monitor (active 12c+): SELECT * FROM v$sql_monitor WHERE status = 'EXECUTING'; A close relative is SEQUENCE (Oracle), which oracle: generates sequential numbers. Independent of tables. Accessed via NEXTVAL and CURRVAL. A close relative is ROWNUM / FETCH FIRST, which oracle: ROWNUM assigns sequential numbers to rows. Used for limiting results (pre-12c). A close relative is SYSDATE / CURRENT_DATE, which oracle: returns the current date and time of the database server.