When to go for Full Table Scan? |
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- čas přidán 21. 07. 2024
- In this episode of daily DBA, I pick up 6 important #DBA related questions and give my answers! Do not forget to checkout BONUS QUESTION at the end of the video!
00:00 Intro
01:19 Can we directly move from 12c to 19c or we have to firstly move to 18c and then 19c.
02:57 What is the impact of IMPDP parameter transform=disable_archive_logging on physical standby?
05:18 Can we change the redundancy level of asm diskgroup if yes then how?
07:27 What is the meaning of resolving gap using primary incremental backup?
10:26 Some of the DBAs say full table scan is better than index scan. Could you please clarify in which situations its better?
15:01 Why I'm missing AWR snapshot? Once I restarted the DB its started to generate the AWR snapshot?
Bonus Question
18:48 When ever i work in real time environment and when ever i try to toch the keyboard my hands start shaking & i tend to feel nervous in dealing with oracle databases?
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You are doing great things that helps many DBA. GBU..😊
Could you please explain cpu tuning parameter on database.
Simply loving it..big big thank you.
How to enable trace for a particular session and in which location the trc file will be placed ??
Hi sir,
Your videos are helping me a lot
how the LOB objects are stored in the database with respect to a table?
Sir, please explain the flashback transaction query and flashback data archive. Is there any difference?
thanks a lot sir, you are doing well. keep it up.
what is the parameter in oracle to set for no.for concurrency. How many connections can listener handle.?
Difference between integrated capture and classic capture in golden gate? In integrated capture do we need to create the logminer database in source database or Oracle uses logminer mechanism to convert the records into LCR?
We can directly upgraded from 12c to19c
What is the difference between oracle DBA and oracle apps DBA roles?
What is the difference between checkpoint and SCN?
How to check license information from RAC. and what are the components that are included to existing license that are exists in both primary and standby.
Raise non-technical SR with Oracle and they should help you on this!
@@dbagenesis thank you. but without support can't we check the license from Database ?
Hi sir
Please answer my question and don't feel bad because of my personal experience i am asking this!!!!
nowadays most of the companies don't want to take fresher dba's they are always look for senior dba's if companies don't give a opportunity for freshers then from where senior dba's will come?
yes i agree dba is back bone to the company but in my opinion instead of reject the fresher dba's by the companies
The companies would have train them acording to their requirements i think it may useful for both students and companies because of this reson some fresher dba following some fake methods like taking fake experience certificates from some institutions to get a job in this case who are making mistake either companies or students?
is really recommendable Oracle dba course for students who want start their carrier without any experience?
Hi Arun,
Regarding full table scan: When there is an index already exists on gender column of course for 20% of female data can be retrieved faster but what if I want male data which is 80% as already index exists. In this case, will optimizer is smart enough to compare costs and execution plan of both steps and skip index scan and choose full table scan. Else do we need to use hints to avoid index scan ?
Answered via email!
QUESTION: WHAT IF WE HAVE ORACLE DATABASE IN CLOUD..IS ORACLE ASM STILL RECOMMENDED OR BENEFICIAL?
Hm, let get back to basics. ASM = storage management software
As cloud already provides storage and they have their own storage management software, implementing ASM in cloud would not give any advantage except client wants to still use ASM for storage management.
One point where you would want to use ASM in cloud is, ASM is tightly integrated with Oracle Database. A storage management software (used by cloud) is tightly integrated with the operating system! I guess you get the difference.
What is the exactly meaning of high redundancy in ASM disk group....
High redundancy means you maintain 2 more copies of your primary disk within the ASM storage.
So, your diskgroup will have a total of 3 disks.
Hope this helps!
Hi Arun How I can access your support search engine that you use in your videos and search ?
support.dbagenesis.com
How can we find CPU intensive SQLs of the application consuming currently very high CPU slowing down the database and other queries.
www.support.dbagenesis.com/post/top-resource-intensive-sql
Hello genius...
If we loss one of control file when databases is up and running....then what will happen with running db and what is the solution to resolve this issue...
Thanks in advance..
Ramesh Shete Db will be up and running till u bounce the db,u can multiplex the control file
@@deepanadonis thank u so much to clear my doubts...
Can you please explain about parallel processing
Parallel Processing the best and easiest ways to boost performance offered by Oracle Database. In Parallel Processing, the request is broken down into multiple units to be worked on by multiple database processes.
Arun waiting for your videos plzz post...
Does Select Statement Generates Redo?
What do you think?
@@dbagenesis Yes Redo logs are generated in some cases
No. DMLs only. If we use INSERT using nologging then no redo generated.
Arun -- You sometime seems to be going very fast in teaching and straight forward answers.
For 1st question:
Yes, we can upgrade Oracle database from 12c to 19c because 12c is a supported intermediate release version to upgrade to 19c.
All of you upgrading your databases with AutoUpgrade or planning to do so can now download the newest version of our AutoUpgrade tool. (applies on 19c,18c,12cR2(DBJAN2019RU))
For more information, refer to Doc ID 2485457.1
Please try to talk about AutoUpgrade tool.
Thanks