SQL_ID row locks

Hi,

Every day from 23.00 to 01.00 the performance of the database becomes slow, when i traced i found the following "The SQL statement with SQL_ID "4pgt142s271gy" was blocked on row locks.", which i think is the reason for poor performance and also i found the query with this SQL_ID.

Dut to this my Application at this time Hangs.

What should be my next step,i can't change this query because till last week the database was going fine.

Please advice me ASAP.

so... what changed during the last week?

See what is locking the row.
Select blocking_Session from v$session where sid=YOUR SESSON SID
can look also at v$lock

Regards

row locks means you have more than one session modifying same set of rows so if one modifies row 1 and the other tries to modify the same row it will have to wait until the first completes his transaction

application issue, not a performance issue

thanks