, the selected-CodePudding

Meet a problem for bosses on

CodePudding user response:

C, the answer you actually do a test to know myself,
Tip: before and after the Oracle DDL implicit commit

CodePudding user response:

reference 1st floor minsic78 response:

C, the answer you actually do a test to know myself,
Hint: Oracle DDL implied both before and after the commit

Thank you thank you for your answer

CodePudding user response:

Behind a rollback, roll back then return to execute the command before,

CodePudding user response:

reference 3 floor poker_ towers response:

behind a rollback, roll back then return to execute the command before,

Which command execution roll back to before?

CodePudding user response:

Rollback is the inverse operation, commit Rollback mainly do the following things: to cancel all has been modified, the complete way is as follows: read back the data from the undo segment, and then actually reverse the previous operations, and will undo items marked as I use it, if the previous insert a line, the Rollback will be deleted, if the update a line, a Rollback will cancel the update, if you remove a line, roll back the insert it again,
Will roll back to the commit operation state, you've done your this several SQL did not submit, so will be rolled back to the initial state, and of course this is only for this kind of insert/delete/update data operation, create a table rolled back, that is to say after the rollback b table still exist, but the former several insert data of SQL are rolled back off,

CodePudding user response:

refer to fifth floor poker_ towers response:

Rollback is the inverse operation, commit Rollback mainly do the following things: to cancel all has been modified, the complete way is as follows: read back the data from the undo segment, and then actually reverse the previous operations, and to undo the entry is marked as I use it, if the previous insert a line, the Rollback will delete them, if have updated the line, the Rollback will cancel the update, if you remove a line, roll back the insert it again,
Will roll back to the commit operation state, you've done your this several SQL did not submit, so will be rolled back to the initial state, and of course this is only for this kind of insert/delete/update data operation, create a table rolled back, that is to say after the rollback b table still exist, but the former several insert data of SQL are rolled back off,

Began to test, see if you can imagine the result

CodePudding user response:

Type a, b, only 2 tables, ABC, 2 this row data, insert in front of the line 1 the rollback, didn't watch carefully thought to create table to insert the row 2 b

CodePudding user response:

https://www.cnblogs.com/fan-yuan/p/7879353.html

CodePudding user response:

refer to the eighth floor AHUA1001 response:

https://www.cnblogs.com/fan-yuan/p/7879353.html

This did not say what database products, also a little problem,
Such as PG, begin a transaction, the DDL can rollback