User and Schema

How to Resolve ORA-00942: table or view does not exist

by Ed Chen
March 23, 2019May 15, 2023
4 Comments

ORA-00942 ORA-00942 means that SQL engine found no table or view in your usable scope. In other words, table or view does not exist. The… Read More »

How to Check Oracle Segment Size

by Ed Chen
January 14, 2019December 10, 2022

Find Biggest Segments A segment in Oracle database is a set of extents that contains all the data for a specific logical storage structure within… Read More »

Oracle Find LOB Segment Table

by Ed Chen
January 11, 2019January 17, 2023

Sometimes, you may see segment type like LOBSEGMENT in the top 10 segments list. They are Large Object (LOB) which may be Binary Large Object… Read More »

How to Find Biggest Tables in Oracle

by Ed Chen
January 8, 2019December 10, 2022

Top 10 Biggest Tables in Whole Database When the disk space is running out, you might want to calculate Oracle table size and list the… Read More »

How to Kill Session in Logon Trigger

by Ed Chen
April 2, 2018April 3, 2018

Here I introduce a trigger which can log logon information on specific schemas. It will kill their sessions if they are not from specific subnet.… Read More »

How to Resolve ORA-04043: object does not exist

by Ed Chen
December 30, 2017April 19, 2023

ORA-04043 ORA-04043 means that the schema object that you want to use is not existing, this could be a typo, privilege or case-sensitive problem like… Read More »

How to Resolve ORA-02266: unique/primary keys in table referenced by enabled foreign keys

by Ed Chen
December 17, 2016May 25, 2023

ORA-02266 ORA-02266 means that you can't truncate the table because reference keys constraint still depend on the data of the table. Truncate a Single Table… Read More »

Oracle Who am I

by Ed Chen
October 16, 2016January 6, 2022
6 Comments

Sometimes, you switched the connection to another schema for more operations and forgot where you are. Here are some ways to know who am I… Read More »

How to Duplicate a Schema from One to Another

by Ed Chen
August 7, 2016May 14, 2021

Suppose you are planning to duplicate user01 schema into user02 schema. Tools like TOAD, SQL Developer can be helpful. But you may also like to… Read More »

How to Resolve ORA-12034: materialized view log on younger than last refresh

by Ed Chen
July 11, 2015January 20, 2021

ORA-12034 Found an error ORA-12034 in alert log: ORA-12034: materialized view log on younger than last refresh Rationale ORA-12034 means that your last refresh older… Read More »

JavaScript is not enabled. Please enable it and reload the page.