Which of the following 3 options is the fastest_PHP Tutorial

D0000D sent to the forum section--------------------------------------------- -------------
No.0 plate dedecms
D8888D post title------------------------------------------------- ----------
Which of the following three options is the fastest?
D8888D main post content------------------------------------------------- ----------


mysql table
a, b, c, d, e, f fields

a is the primary key, type is vachar(20)

Now we need to update, there are 10,000 records in total
To execute the following statement 10,000 times without using transactions

Option 1:
UPDATE table SET b = 222, c = 333, d = 444 WHERE a = xx

Option 2:
REPLACE INTO table VALUES($a,$b,$c,$d,$e,$f)

Option 3:
Waiting for you to write

Let me answer




D8888D reply content------------------------------------------------- ----------
1.

D8888D reply content------------------------------------------------- ----------
I also want to know about this issue, please help me.

D8888D reply content------------------------------------------------- ----------
Option 3! ~[img]http://www.phpchina.com/bbs/images/smilies/default/victory.gif[/img]

D8888D reply content------------------------------------------------- ----------
There should be no difference, right?

D8888D reply content------------------------------------------------- ----------
The author seems to be working on data synchronization.
There are three requirements for data synchronization: addition, deletion, and modification.
Option 1 only meets the needs for modification.
Option 2 meets the needs for additions and modifications.

D8888D reply content------------------------------------------------- ----------
It may be more efficient to encapsulate it into a REPLACE INTO statement, because you only need to send an instruction to the database server once, like this:

REPLACE INTO table VALUES (1, 1, 1, 1),(2, 1, 1, 1),(3, 1, 1, 1),(4, 1, 1, 1);

D8888D reply content------------------------------------------------- ----------
[url=http://bbs.phpchina.com/redirect.php?goto=findpost&pid=1067540&ptid=126860]Link tag 6#[/url] faallan

Yes!

But I only need to change it, not add anything.

D8888D reply content------------------------------------------------- ----------
[url=http://bbs.phpchina.com/redirect.php?goto=findpost&pid=1067568&ptid=126860]Link tag 7#[/url] Road Trip Baby

replace into is actually a secondary query, first delete and then add
But the advantage is that you can merge several sentences at a time when you are not using the transaction
Since we delete first and then add, I don’t know what will happen under high concurrency. We need to take care of reading
I haven’t actually tested it yet, so I don’t know how much faster it can be

http://www.bkjia.com/PHPjc/632569.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/632569.htmlTechArticleD0000D sent to the forum section ------------------- ------------------------------------ No.0 plate dedecms D8888D post title ------ ------------------------------------------------- the following ...