What sort of lock does truncate require? If it is not an access exclusive
lock, what locks would block the truncate?

Thanks,

Chris

If I do :
Session 1:
decibel=# begin;
BEGIN
decibel=# select * from i where i=1 for update nowait;
i
---
1
(1 row)

decibel=# begin;
BEGIN
decibel=# select * from i where i=2 for update nowait;
i
---
2
(1 row)

Session 2 :

decibel=# select * from i where i=1 for update nowait;
ERROR: could not obtain lock on row in relation "i"
decibel=# select * from i where i=3 for update nowait;
ERROR: current transaction is aborted, commands ignored until end of
transaction block
decibel=# ==> Why ? :'(

Why i can't do any "Select for update" (current transaction aborted) after
having receive a not obtain lock ???
Thank you for your answer !

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On Thu, Sep 28, 2006 at 03:26:36PM +0000, Mathias Laurent wrote:
> If I do :
> Session 1:
> decibel=# begin;

Does decibel have some meaning in some language other than english?

> BEGIN
> decibel=# select * from i where i=1 for update nowait;
> i
> ---
> 1
> (1 row)
>
> decibel=# begin;
> BEGIN
> decibel=# select * from i where i=2 for update nowait;
> i
> ---
> 2
> (1 row)
>
> Session 2 :
>
> decibel=# select * from i where i=1 for update nowait;
> ERROR: could not obtain lock on row in relation "i"
> decibel=# select * from i where i=3 for update nowait;
> ERROR: current transaction is aborted, commands ignored until end of
> transaction block
> decibel=# ==> Why ? :'(
>
> Why i can't do any "Select for update" (current transaction aborted) after
> having receive a not obtain lock ???
> Thank you for your answer !

Because as soon as there is an error in a transaction, the entire
transaction is void. You have to rollback the transaction (or return to
a savepoint).
--
Jim Nasby jim@nasby.net
EnterpriseDB http://enterprisedb.com 512.569.9461 (cell)

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