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UPSS!!! 3.00 is wrong! the phrase: "another transaction can apply exclusive lock" is not true! Correction: Only shared lock (read) request could be applied when a shared lock has already obtained.
Love your videos, you're saving my life.
If a transaction has share lock, you CAN'T apply exclusuve lock! FIRST EXAMPLE (with x in circle) IS WRONG!
Lol all these people correcting his first example without finishing the video. He corrected himself later my dudes.
In Transaction T1, we need to acces A first. So shouldn't you have apply shared lock on A to read it first and then Lock-x to write it ?
An exclusive lock allows for T1 to read and write to A
It also helps to note that a general assumption is that in order to write to a data item, you must read it first
how someone can write a locked item x shared lock in t1 how t2 is accesing it writing it need to first unlock or release the item x incompatible.
Exactly We cannot obtain an exclusive lock on a data item which is already having shared lock
Both the transaction is different. they are not performing parallelly...
can you show you how to lock a table(or)database in mysql
amazing
*If Reading data item does not need locking* then why do we have shared lock ??
It still needs locking because of write operations
Can someone explain me why there is a need for locks???I am not able to understand... :(...
That means shared exclusive locks have no advantages
plz upload next video
+Harshil Saini lets hope for best
Sir pls reply
UPSS!!! 3.00 is wrong! the phrase: "another transaction can apply exclusive lock" is not true! Correction: Only shared lock (read) request could be applied when a shared lock has already obtained.
Love your videos, you're saving my life.
If a transaction has share lock, you CAN'T apply exclusuve lock! FIRST EXAMPLE (with x in circle) IS WRONG!
Lol all these people correcting his first example without finishing the video. He corrected himself later my dudes.
In Transaction T1, we need to acces A first. So shouldn't you have apply shared lock on A to read it first and then Lock-x to write it ?
An exclusive lock allows for T1 to read and write to A
It also helps to note that a general assumption is that in order to write to a data item, you must read it first
how someone can write a locked item x shared lock in t1 how t2 is accesing it writing it need to first unlock or release the item x incompatible.
Exactly
We cannot obtain an exclusive lock on a data item which is already having shared lock
Both the transaction is different. they are not performing parallelly...
can you show you how to lock a table(or)database in mysql
amazing
*If Reading data item does not need locking* then why do we have shared lock ??
It still needs locking because of write operations
Can someone explain me why there is a need for locks???
I am not able to understand... :(...
That means shared exclusive locks have no advantages
plz upload next video
+Harshil Saini lets hope for best
Sir pls reply