From: Achilleus Mantzios <achill@matrix.gatewaynet.com>
To: Lane Van Ingen <lvaningen@esncc.com>
Cc: pgsql-sql@postgresql.org
Subject: Re: How to Force Transactions to Process Serially on A Table
Date: Mon, 19 Dec 2005 16:25:13 +0200 (EET)
Message-ID: <Pine.LNX.4.44.0512191615510.7853-100000@matrix.gatewaynet.com> (raw)
In-Reply-To: <EKEMKEFLOMKDDLIALABICEGLCGAA.lvaningen@esncc.com>
O Lane Van Ingen Ýãñáøå óôéò Dec 19, 2005 :
> I am using PL/SQL functions on Windows 2003, version 8.0.1.
>
> I have not used explicit PostgreSQL LOCKing before, but I need some advice
> on how properly to use some explicit locking. I think that duplicate key
> violations I am now getting are the result.
>
> I want to force transactions being used to update a table to be processed on
> a first-come, first-served basis. I want my Pl/sql function to execute to
> completion on each transaction before another starts.
>
> Need some advice on how to do this. From what I can read in the docs, it
> looks like I need to solve the problem by using the following, but doing so
> gives me an SPI_execution error:
> BEGIN;
> LOCK <table> IN SHARE ROW EXCLUSIVE MODE;
> lock adns_report_hour_history in share row exclusive mode;
> INSERT INTO <table> VALUES ... - or - UPDATE <table> SET ....
> COMMIT;
> Will this make the next transaction wait until the previous transaction has
> completed? Do I need to set any config parameters?
>
> If you can include an actual code snippet in the response, it would help ...
what you want is to set the xaction isolation level.
BEGIN;
SET TRANSACTION ISOLATION LEVEL SERIALIZABLE;
......
COMMIT;
Be prepared for serialization failures though.
>
>
>
> ---------------------------(end of broadcast)---------------------------
> TIP 2: Don't 'kill -9' the postmaster
>
--
-Achilleus
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To: pgsql-sql@postgresql.org
Cc: achill@matrix.gatewaynet.com, lvaningen@esncc.com
Subject: Re: How to Force Transactions to Process Serially on A Table
In-Reply-To: <Pine.LNX.4.44.0512191615510.7853-100000@matrix.gatewaynet.com>
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