Category Archives: Memory Management Interview Questions

Full back – Complete database Incremental – Only affected tables from last incremental date/full backup date. Cumulative backup – Only affected table from the last cumulative date/full backup date.

The space used transaction entries and a deleted record does not become free immediately after completion due to delayed cleanout. Trailing nulls and length bytes are not stored. Inserts of, updates to and deletes of rows as well as columns … Continue reading →

It is area in memory that is used by a Single Oracle User Process.

The data dictionary cache is stored in an area in SGA called the Shared SQL Pool. This will allow sharing of parsed SQL statements among concurrent users.

The System Global Area in a Oracle database is the area in memory to facilitates the transfer of information between users. It holds the most recently requested structural information between users. It holds the most recently requested structural information about … Continue reading →

1. Edit init.ora file set control_files parameter with multiple location 2. shutdown immediate 3. copy control file to multiple locations & confirm from init.ora contol_files parameter 4. start the database. 5. run this query for changes confirmation – select name … Continue reading →

Multiplexing Redo log file called Mirroing. ( Keeping multiple copies in different disks)

LGWR process wirtes all change vectors from theredo log buffer to online redo log file sequentially.

Shadow set of disks save as a backup in the event of disk failure. In most Operating System if any disk failure occurs it automatically switchover to place of failed disk. Improved performance because most OS support volume shadowing can … Continue reading →

When a user updated a particular table (for example 100 rows) the old value will be retained in the roll back segments(Oracle 8) and now it is Undo segment (oracle 9i). If the user issue a rollback command the old … Continue reading →