Read Only Transactions

[R_M]

Hi:

I am new to Oracle and have a probably trivial concurrency question.

How is an ROT implemented ?

Suppose I create an ROT
and then issue the following commands:
select * from table A where colx=3
select * from table A where colx != 3
select * from table B
select * from table A where colx=2
select * from table B

Is the contents of tables A and B saved aside so any concurrent update
transactions succeed ?
Or are tables A and B blocking updates until I close the ROT.

Thanks

Ricardo

[Ana C. Dent]

R_M wrote:

Hi:

I am new to Oracle and have a probably trivial concurrency question.

How is an ROT implemented ?

Suppose I create an ROT
and then issue the following commands:
select * from table A where colx=3
select * from table A where colx != 3
select * from table B
select * from table A where colx=2
select * from table B

Is the contents of tables A and B saved aside so any concurrent update
transactions succeed ?
Kind of.
Changes to the tables are "saved" so you continue to be presented
with data as it existed at the start of your ROT.
Or are tables A and B blocking updates until I close the ROT.

NO blocking occurs.
In Oracle Readers NEVER block writers!