Oracle Memory Management Interview Questions

We can get the pfile from the diagonostics_dest path, in this we select the appropriate parameters and then jst create a copy in $ORACLE_HOME/dbs location using another initdbname.ora
jst run it again its enough it works.

All the changes to the init.ora file is recorded in the alert.log file. So,go to the alert log file in bdump directory and delete the unnecessary parameters from the file and copy that file to the desired location and restart the database.

We can avoid explicitly showing password in the script by putting it in Parfile. If password has Pound "#" sign in it then parfile will treat the pound sign as a start of a comment so it wont work in that case.

Alter table < Table_Name> move tablespace ; 
 
Alter index rebuild tablespace ;

Redo log buffer is circular buffer,lgwr writes these buffers in cyclic faishon.redo log buffers contains redo entreies which are used to reconstruct or redo chandes. 
 

it is a memory location where the temporary changes are stored in abuffer

Number  of  times processes repeatedly query the dictionary table is called recursive  hints.  It  is due to the data dictionary cache is too small. By increasing  the SHARED_POOL_SIZE parameter we can optimize the size of Data Dictionary Cache.

Hi,

Dictionary cache is memory arear in shared pool.dictionary cache are used to hold db blocks of recently used data dictionary tables.

thanks

Alok.

Hi,

Database buffers are used to store copy of data of data blocks that has been used recently.the set of database block buffers are called db buffer cache.redo log buffers are used to store temorary entries for redo that supose to written to redo logfiles.

thanks

Alok.

Calculate the total header size.
Calulate the available data spaceper data block.
Calulcate the combined column length by the avarge row.
Calultate total averagerow size.
Calculate avarge number of rows that can fit in data block.
Calulate the number of blocksbytes that required for a table.

Backups that are done using exp/imp or Data pump as called logical backups. It take the backup of logical structure of database instead of physical.

Logical backup means backing up the database objects like tables, views , indexes...etc using the EXPORT utility given by Oracle. The objects exported in this way can be imported into either same data...

IFCONFIG LONG_BIT
if we use this command we can find size of block size in os level

Raw devices are controlled by the database engine so the OS kernel can be bypassed when using raw devices. System files reside on filesystem, filesystem is addressed by the kernel. So everytime a data...

RAM means Random access memory, which is used as a temporary memory space to load Operating system kernel, driver modules and services needed on the system. Whenever you switch off the system all the ...

Disk shadowing or mirroring is done either using a software or a hardware utility called RAID.  Disk shadowing enables another disk to take-over from a failed hard disk avoiding any downtimes. Generally Hardware fial-overs are enabled on all servers.

instead of taking seperate backups mirroring always helps taking backup simultanuesy.

If its the same database use:

alter table the_table move tablespace other_tablespace;
alter index the_index rebuild tablespace other_tablespace;

Oracle raw devices are managed only with Oracle tools, at OS level they are just dd (character special files) devices. Raw devices are more difficult to administer than data files stored on a file system or in an ASM disk group.

Yes. Using raw files/devices for database can have a slight performance gain. Raw files are unformatted disk partitions that can be used as one large file. Raw devices have the benefit of no file syst...