Ed Chen Logic

How to Check SGA Components Memory Distribution on Database 9i

by Ed Chen
October 28, 2012May 13, 2019

SGA Components For database 9i, there is no dynamic view gv$sgainfo like 10g or 11g that can represent current memory distribution of every component. Another… Read More »

How to Check Tablespace Size in Oracle

by Ed Chen
October 27, 2012June 22, 2022

After having the whole picture about the size of the database, we can further check Oracle tablespace usage solely by SQL. Oracle Tablespace Usage Of… Read More »

How to Startup a Misconfigured Database ORA-00837

by Ed Chen
October 26, 2012December 28, 2020

A misconfigured database is a database which was set with wrong values of initialization parameters in SPFILE, it will prevent the database from startup. Let's… Read More »

How to Write Control File into Raw Device

by Ed Chen
October 25, 2012November 22, 2022

Control File in Raw Device? Since raw devices cannot be read/write as a normal file operation, you cannot write a controlfile directly into a raw… Read More »

How to Map Timestamp to SCN or Vice Versa

by Ed Chen
October 24, 2012July 16, 2019

If you are trying to do an incomplete recovery (also called Point-In-Time Recovery, PITR), you may want to know a System Change Number (SCN) using… Read More »

How to Check Current System Change Number (SCN)

by Ed Chen
October 23, 2012July 16, 2019

System Change Number Some DBAs will schedule a cron job to capture System Change Number (SCN) periodically to save as a Timestamp/SCN mapping reference. To… Read More »

How to Resolve ORA-19809 Limit Exceeded for Recovery Files

by Ed Chen
October 22, 2012January 18, 2020
10 Comments

ORA-19809 We usually watch the space usage of log archive destination very closely because the database will be suspended if the space is full. Particularly,… Read More »

How to Set Client-Side Transparent Application Failover (TAF)

by Ed Chen
October 21, 2012February 21, 2021

Transparent Application Failover (TAF) Besides connect-time failover to the standby database, there is a function called Transparent Application Failover (TAF) can do run-time failover to… Read More »

ANALYZE vs DBMS_STATS

by Ed Chen
October 20, 2012January 23, 2021

Oracle recommends to use DBMS_STATS instead of ANALYZE since 8i. Sometimes, we might get confused by the two similar tools. So I took some times… Read More »

How to Resolve ORA-30036 UNABLE TO EXTEND SEGMENT BY 8 IN UNDO TABLESPACE 'UNDOTBS1'

by Ed Chen
October 19, 2012March 28, 2021

ORA-30036 This error ORA-30036 could be very serious in a situation that is described below and may make users panic: One day, a DBA was… Read More »