@CamiloSanchez1979 Yes, it seems so. The only question that I have concerns the second table with countries and years...is it possible that the search will be done by first looking at the years column even though, in our query, we've put country on the first place (...WHERE country='CHINA'...). Strange...
@AnExplorer1000 The order of conditions in the SQL statement is irrelevant. Actually "order" is a notion that is completely foreign to the relational theory as designed by Ted Codd. Query optimizers check conditions, check indexes, sometimes rewrite queries, and do as they can to take advantage of existing indexes - if things such as selectivity and distribution of value hint at using the indexes being good for response time.
Though the information provided is excellent in terms of the value but the title is misleading. The information provided in the video is about pros and cons of indexing and not about how to index ?
Prashant Vikal What are indexes, how they work, and, yes, their pros and cons. I should add that in nine minutes you cannot expect an exhaustive review of a topic which is complex; in fact, many young professionals don't quite "get" what is here, which is why I did the video. For a more in-depth analysis, I have written three books on SQL, adding up to about 1,000 pages. And if your concern is the CREATE INDEX syntax, check the docs of your particular DBMS.
probably one of the best tutorials i've seen for indexes
@CamiloSanchez1979 Yes, it seems so. The only question that I have concerns the second table with countries and years...is it possible that the search will be done by first looking at the years column even though, in our query, we've put country on the first place (...WHERE country='CHINA'...).
Strange...
thanks for the great tutorials! that's the most i ever learned about databases in just an hour!
@ponghissimo1 That's why he has put closed captions... So...
This was very useful. This video once more proves that databases should be approached more academically.
@AnExplorer1000
The order of conditions in the SQL statement is irrelevant. Actually "order" is a notion that is completely foreign to the relational theory as designed by Ted Codd. Query optimizers check conditions, check indexes, sometimes rewrite queries, and do as they can to take advantage of existing indexes - if things such as selectivity and distribution of value hint at using the indexes being good for response time.
Though the information provided is excellent in terms of the value but the title is misleading.
The information provided in the video is about pros and cons of indexing and not about how to index ?
Prashant Vikal
Was the video titled "how to index"?
roughsealtd What you think "SQL indexing" means ?
Prashant Vikal
What are indexes, how they work, and, yes, their pros and cons. I should add that in nine minutes you cannot expect an exhaustive review of a topic which is complex; in fact, many young professionals don't quite "get" what is here, which is why I did the video. For a more in-depth analysis, I have written three books on SQL, adding up to about 1,000 pages. And if your concern is the CREATE INDEX syntax, check the docs of your particular DBMS.
roughsealtd whatever, I can't convince you and that's not my job. Good luck :/
If it were about "how to" it would have included the specific DBMS in the title, since indexing creation syntax is non-standard
would not have dropped my class if I seen this video!
excellent video. Especially the way it was presented.
Great video. Thank you for adding the sub-titles too.
Ok, so the question remains, should one index or not? ..i guess the answer is relative
Very informative video and love the accent! Thanks so much!
extremely funny videos. i am definitely going to have a look at your books. merci pour le bon travaille.
excellent.. teaching method and contents...
Thank you. Easy to understand and follow.
fire ze mizziles!
@ponghissimo1 He's French..
Very easy to understand.
Thank you!
Brilliant!
Useful
great job sir :)
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No, thank you for teaching.