Message-ID: <5140B917.5060405@gmail.com>
Date: Wed, 13 Mar 2013 13:36:23 -0400
From: =?ISO-8859-1?Q?=22Gabriel_E=2E_S=E1nchez_Mart=EDnez=22?=
	<gabrielesanchez@gmail.com>
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To: pgsql-admin@postgresql.org
Subject: tables mysteriously truncated
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I have run into an annoying issue several times.  After successfully 
populating a table with the COPY command, letting the server run 
auto-vacuum analyze, and being able to query the table without any 
issues for several days, the table suddenly appears to be empty.  In 
pgAdmin I see a large estimated number of rows, as it should be, but any 
SELECT to that table returns no rows, and SELECT COUNT(*) returns 0.  If 
I run an ANALYZE on that table and refresh pgAdmin, the estimated number 
of rows is reset to 0.  It is as if someone had run TRUNCATE on the 
table, but I cannot find TRUNCATE or DELETE statements on the logs, and 
the only users with the privileges to do so (my colleague and I) have 
not executed such statements.  The rest of the users can only select and 
reference.

I am running PostgreSQL 9.1.8 on Ubuntu 12.10 x86_64 server.  I have a 
master unlogged table with all the columns, no primary key, and no 
index.  This master_table has no data per se.  Then I have several 
partitions, created as follows:

CREATE UNLOGGED TABLE partition_1 ()
INHERITS (master_table)
WITH (OIDS = FALSE);

Each partition contains up to 20 million rows, and I have about 30 
partitions.

I have three such sets of tables on the same database, and the issue has 
happened multiple times with two of the three sets of tables. Curiously, 
the one that has never been affected is a bit different: the master 
table contains a column id bigserial, which is a primary key.  Also, 
this table is logged.

Has anyone run into similar issues in the past?  Could this be a bug?

Thanks in advance.

-Gabriel


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