Re: Progress of asynchronous queries - Mailing list pgsql-interfaces

From Jeroen T. Vermeulen
Subject Re: Progress of asynchronous queries
Date
Msg-id 6009.125.24.242.104.1158397058.squirrel@webmail.xs4all.nl
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In response to Re: Progress of asynchronous queries  (Adriaan van Os <postgres@microbizz.nl>)
Responses Re: Progress of asynchronous queries  (Adriaan van Os <postgres@microbizz.nl>)
List pgsql-interfaces
On Fri, September 15, 2006 19:56, Adriaan van Os wrote:

> Besides, when more than one user is connected, multiple SQL commands may
> behave different than a
> single SQL command
> (<http://www.postgresql.org/docs/8.1/static/transaction-iso.html>)

But you'd be doing this in a transaction anyway: you can't declare a
cursor without starting a transaction first.  Yes, you could deliberately
declare "WITH HOLD" and keep using your cursor after commiting or aborting
the transaction.  But even then, so far as I know, the cursor presents a
snapshot view of its result set so you get an effective isolation level of
"serializable" even then.

The number of users has nothing to do with the matter--if that were a real
concern, you'd be using a serializable transaction anyway, so you wouldn't
have to worry about it even if cursors did behave as "read committed."


Jeroen






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