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SQL: Explain Plan for knowing the Query performance

594 ratings | 94289 views
In this tutorial, you'll learn how to compare queries to know the better performance query..
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Text Comments (39)
Sumanta Dolui (5 months ago)
This is wrong concept. You can't tell that the conditional column is indexed or not based on full table scan operation. Sometimes conditional column is indexed but oracle perform the full table scan on that table. It is totally depent on how many rows oracle fetched from that table. Full scan n index scan depent on various things like row size, block size, how many rows returning ur query etc. Behind this, has mathematical calculation. I can explain it if require.
Lova Chittumuri (1 year ago)
Thank you... Nice Explanation ...
vijay virgil (1 year ago)
keep posting more info...thanks in advance
dhana lakshmi (1 year ago)
good job keep it up.
Imran Khan (1 year ago)
Many thanks in advance, please upload Bulk collect and Bulk Binding Video
ravishankar (1 year ago)
Nathan Russell (1 year ago)
thanks for really great tutorial! very informative! have you tried this tool - https://www.devart.com/dbforge/oracle/studio/oracle-sql-profiler.html#header ? in addition it gives session statistics for your query
nagushanu (2 years ago)
Thanks Radhika Ravikumar! way of explain is easy to understand! It is helpful if you explain how to tuning the query with steps.
neeraj gupta (2 years ago)
One suggestion. You could have kept it written before and in slides. writing on console kills viewers time.
Bharath Ram (2 years ago)
What do you do exactly? Would you be willing for a 15 min chat on skype (ID: bharathrammanoharan)? I promise there is no catch. I would like to know about your challenges so I can help people like you via my blog. Thanks.
neeraj gupta (2 years ago)
I was looking for how to understand explain output. Got it in postgres documentations.
Bharath Ram (2 years ago)
Hi neeraj - just curious what triggered you to look for and watch youtube videos related to SQL tuning. I am an Oracle DBA too trying to help people by creating content similar to this. I would like to know how you think about SQL tuning etc.
Praveen (2 years ago)
I think you are wrong. Just because optimizer is going for a full table scan does not mean there is no index on deptno column. Optimizer can still go for full table scan even with the existence of index on deptno if it detects data skew and believes FTS is cheaper ..
Bharath Ram (2 years ago)
Hey Praveen - you're exactly right. So many people get this wrong - if you're retrieving more than 15% of the data from a table, optimizer will very likely choose FTS over an index. Needless to mention the important of Statistics. May I know what do you do and why are you interested in SQL tuning.
Makeshwar Sah (2 years ago)
still index is not created.....
Shaikh Zainulabedin (2 years ago)
very good, demo please update if you have more.god will give you reward for this. radhikaravikumar
Subhroneel Ganguly (2 years ago)
Many many thanks.
siddhartha rao (2 years ago)
still index is not creating..
ravikiran shejal (2 years ago)
before semantic checking hash value is genrated or after semantic ..........
Krishna Kumar (3 years ago)
Through this video , I understand basics of explain plan. Thank you.
Jayanth Gadam (3 years ago)
Index and explain plan... very bad explanation
Vivek H (3 years ago)
Kishore Dondla (3 years ago)
thanks madam.. Appreciated
Hanmant Arsid (3 years ago)
To find a index, we don't have to get a explain plan for it. there are views in instance to find that.
Namaste India (3 years ago)
Take care of your cold lol
Niraj Singh (3 years ago)
Suraj Chandak (4 years ago)
It was very short with simple example. What if I use dept_no in (10,20) what if I make a functional index.. what are the limitation and how to handle them.. Ur presentation was not worth watching... Should have explained in detail about the Cost and Rows.. arhhhh...u pissed me
Namaste India (3 years ago)
Chill and be thankful mate
吳廣德 (4 years ago)
why you don't use "set autotrace on" instead? it's much more convenient, right?
satish ramapragada (1 year ago)
吳廣德 i
Ankush Kamboj (4 years ago)
really  goood
Pradipta Mallick (4 years ago)
Really Good
Farhad Alam (4 years ago)
good video
Farhan Hasan (4 years ago)
your voice is too sexy so just to hear that i will subscribe to your channel
Farhad Alam (4 years ago)
please try to learn manner to talk with Teacher
Nikita Eshkeev (4 years ago)
This is a really bad demonstration, why don't you gather the statistics?
Nayak Gouda (2 years ago)
+Nikita Eshkeev : plz come up with your own video..
Prasad Nandam (4 years ago)
Thanks ...
Musavir Ali (4 years ago)
Hello All, i have oracle 11g Databse and Developer 11g i want to send sms to  party on  insert or update record in the databse ... please any one give me  idea...

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