Basic Concepts of Index

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

Oracle Database Block Corruption

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

Things to know before Upgrading Oracle 12c DB !!

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

Export/Import Interview Questions-II

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

Export/Import Interview questions-I

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