Oracle DBA Fresher and L1 Basic Interview Question and Answers

[@mdak-df2eb]

Could you please upload 2-3 years experience dba interview questions.
Reply

[@jay_jirage821]

thanks for this is very use full as fresher

[@THESTATIONOFSTORY]

Nice 👍

[@babuaz8812]

dbwr will write not ONLY commit transaction but also uncommitted transaction to datafiles. Please verify this?

[@RACSINFOTECH]

The database writer can write uncommitted info also to datafiles as a result of following activities.
When uncommitted data belonging to a tablespace is flushed to disk as a result of
Tablespace offline
Tablespace read only
Tablespace begin backup
Manual checkpoint
Whenever checkpoint is initiated manually, all the dirty blocks containing committed/uncommitted data in buffer cache are flushed to disk .
Flush buffer cache
If buffer cache containing dirty blocks is flushed, dirty blocks containing uncommitted data are written to datafiles.
Before a logfile gets overwritten
A redo log cannot be overwritten until changes recorded in it are written to disk by DBWR. Hence, before a redo log
containing uncommitted data is overwritten, uncommitted changes recorded in it are written to datafiles by DBWR.

[@babuaz8812]

SYSTEM, SYSAUX are only MANDATORY tablespaces not five. can any database run with just these 2 tablespaces or not check?

[@RACSINFOTECH]

you mean we able to start or use the oracle db with these 2 tablespace ? answer is no .. default ts are 5 .. also without those 5 ts we can use the db in oracle.... if you are able to do anything just share here with snaps or reference's will see that

[@babuaz8812]

@@RACSINFOTECH
I apologies not 2 but 3 tablespace are ONLY must, see below. DB version is 12c.
SQL> conn / as sysdba
Connected to an idle instance.
SQL> startup nomount
ORACLE instance started.
Total System Global Area 452984832 bytes
Fixed Size 8621616 bytes
Variable Size 369099216 bytes
Database Buffers 67108864 bytes
Redo Buffers 8155136 bytes
SQL> create database testdb;
Database created.
SQL> select * from v$tablespace;
TS# NAME INC BIG FLA ENC CON_ID
---------- ------------------------------ --- --- --- --- ----------
0 SYSTEM YES NO YES 0
1 SYSAUX YES NO YES 0
2 SYS_UNDOTS YES NO YES 0
SQL> select status from v$Instance;
STATUS
------------
OPEN
SQL> create table emp (eno number);
Table created.
SQL> insert into emp values(100);
1 row created.
SQL> commit;
Commit complete.
SQL> select * from emp;
ENO
----------
100

[@sadashivsbz2095]

List backup of database summary;

[@rohitpanda6810]

Could you please upload interview for 6-7yr experience

[@wbtopg]

No

[@jayakrishnachanumuru]

🙏