Ed Chen Logic

How to Resolve ORA-08186: invalid timestamp specified

by Ed Chen
March 17, 2023March 21, 2023

ORA-08186 Tried to perform a flashback query, but it failed with ORA-08186. SQL> select count(*) cnt from t1 as of timestamp to_timestamp('3023-02-20 00:53:08', 'yyyy-mm-dd hh24:mi:ss');… Read More »

How to Resolve ORA-01466: unable to read data - table definition has changed

by Ed Chen
March 16, 2023March 21, 2023

ORA-01466 Tried to perform a flashback query, but it failed with ORA-01466. SQL> select count(*) cnt from t1 as of timestamp to_timestamp('2023-02-19 22:15:00', 'yyyy-mm-dd hh24:mi:ss');… Read More »

How to Resolve DBT-06006: Unable to create directory

by Ed Chen
March 15, 2023March 16, 2023

DBT-06006 Saw error DBT-06006 when we tried to create a database by Database Configuration Assistant (DBCA). [FATAL] [DBT-06006] Unable to create directory: (/oradata/ORCLCDB/). CAUSE:… Read More »

How to Resolve ORA-00030: User session ID does not exist.

by Ed Chen
March 14, 2023March 16, 2023

ORA-00030 Tried to kill a session, but it failed with ORA-00030. SQL> ALTER SYSTEM KILL SESSION '1821, 8545, @2'; ALTER SYSTEM KILL SESSION '1821, 8545,… Read More »

How to Resolve ORA-27302: failure occurred at: skgpspawn3

by Ed Chen
March 13, 2023March 14, 2023

ORA-27302 skgpspawn3 One of RAC instances crashed in the night and we saw ORA-27300, ORA-27301 and ORA-27302 in the alert log before crashing. 2022-11-21T22:28:01.339829-08:00 Process… Read More »

How to Resolve ORA-28009: connection as SYS should be as SYSDBA or SYSOPER

by Ed Chen
March 10, 2023February 15, 2023

ORA-28009 Tried to connect to a database, but it failed with ORA-28009. SQL> conn sys/password@orclpdb ERROR: ORA-28009: connection as SYS should be as SYSDBA or… Read More »

How to Check SCAN Host Name

by Ed Chen
March 9, 2023March 11, 2023

SCAN Hostname To know the hostname of a SCAN in the cluster, we have some ways to get it. nslookup Given a known SCAN IP,… Read More »

How to Check SCAN IP Address

by Ed Chen
March 8, 2023March 11, 2023

SCAN IP Address In a complex environment, you may have some ways to fast check the actual SCAN IP used in the RAC server. nslookup… Read More »

How to Resolve CRS-4640: Oracle High Availability Services is already active

by Ed Chen
March 7, 2023February 15, 2023

CRS-4640 We observed that osysmond.bin was taking too much memory and the usage of SWAP was increasing. At this moment, to prevent the server from… Read More »

How to Resolve ORA-00054: resource busy and acquire with NOWAIT specified or timeout expired

by Ed Chen
March 6, 2023March 7, 2023

ORA-00054 There're several cases that throw ORA-00054. Alter Table Move Tablespace We tried to move table to another tablespace. SQL> show user USER is "HR"… Read More »