This event signifies that the user process is reading a buffer into the SGA buffer cache and is waiting for a physical I/O call to return. A sequential read is a single-block read. DB file sequential reads wait event comes under the User I/O wait class. In any busy system this is one of the … Read more
Overview of Inventory: The inventory is a very important part of the Oracle Universal Installer. This is where OUI keeps all information regarding the products installed on a specific machine. There are two inventories : 1. The inventory in the ORACLE_HOME (Local Inventory) 2. The central inventory directory outside the ORACLE_HOME (Global Inventory) At startup, … Read more
TX lock contention is an application coding, design and usage problem and can ONLY be fixed by changing application code with more frequent and explicit COMMIT statements and any other minor code changes. Oracle Support cannot fix TX lock wait issues other than helping to identify the objects and commands causing the waits. This wait … Read more
In case if we want to identify duplicates rows of a table and want to remove them from a table. Below are the command which will identify and remove the duplicare rows from a Table. 1.) Identify duplicates Here 251 duplicates exist – these can be deleted with command below : 2.) Removing the Rows … Read more
Oracle uses two different index architectures: b-Tree indexes and bitmap indexes. Cluster indexes, bitmap join indexes, function-based indexes, reverse key indexes and text indexes are all just variations on the two main types. b-Tree is the “normal” index . The “-Tree” in b-Tree A b-Tree index is a data structure in the form of a … Read more
What is a data block corruption? Data block corruptions occur whenever data is not in its expected state. Data Block corruptions are one of the common source of database outages. A database block is corrupted when its content has changed from what Oracle Database expects. The block may have contents that are not internally consistent, … Read more
Why there is a need to upgrade Oracle 12c Database? The most important reason to upgrade 12c is to enjoy continued access to Oracle support. Premier Support for Oracle Database 12c has already ended, and Extended Support will expire in July 2022. After this date, Oracle is under no obligation to provide further updates for … Read more
What is use of INDEXFILE option in imp? Will write DDLs of the objects in the dumpfile into the specified file. What is use of IGNORE option in imp? Will ignore the errors during import and will continue the import. What are the differences between expdp and exp (Data Pump or normal exp/imp)? Data Pump … Read more
What is use of CONSISTENT option in exp? When you export a table, you are guaranteed that the contents of that table will be consistent with the time that the export of that table was started. This means that if you start exporting the table at 12:00 and someone makes changes to the data in … Read more
Below is the error while I was upgrading my test environment. SQL> alter pluggable database application CODDY begin upgrade ‘1.3’ to ‘1.4’; alter pluggable database application CODDY begin upgrade ‘1.3’ to ‘1.4’ ORA-65011: Pluggable database F3094217277_21_4 does not exist. ORA-65169: error encountered while attempting to copy file /opt/app/oracle/prd/coddy/users.dbf ORA-19502: write error on file “/opt/app/oracle/prd/coddy/datafile/o1_mf_users_gc8xyz9o_.dbf”, block … Read more