Greetings!
I just ran across one of the strangest pieces I have ever seen in a piece of
software.
I was connected remotely to a test machine set up at a customer's site. The
machine is running Windows XP and PostgreSQL 8.1. PGAdmin has a connection to
the customer's production database, which resides on another machine. The
database has a simple 3-column table that I thought has 22 million records,
until last week when I found that a backup of the table showed that it actually
has no records. A member of this list introduced me to the concept of
inherited tables. There are 2 rules on the feedback table. One says that if
the charge number is less than 7000, then data should be inserted into the
feedback_backup table and the other says that if if the charge number is
greater than 7000, data should be inserted into the feedback_active table. The
feedback_active table's definition includes "INHERIT (feedback)". The
feedback_backup table does not have an INHERIT clause.
I was curious about how much data was in each of the other two tables. I
opened an SQL window and issued "select count(charge) from feedback_backup".
In a separate window I ussied "select count(charge) from feedback_active". The
two queries were running simultaneously. I already knew that "select count(*)
from feedback" takes about twenty minutes. I minimized my Remote Desktop
window and moved on to other things.
Half an hour later I returned. Neither query had finished, and the query timer
in both windows had not been updated. Task Manager showed me that every
PGAdmin task was not responding. Using Task Manager, I killed PGAdmin.
At the time I first issued the count queries, a Windows Explorer window was
up. It was showing the contents of a folder that had 4 filed:
backup_feedback.bat, backup_in_pieces..bat, restore_pieces.bat and
restore_feedback.bat. After I killed PGAdmin, the names of the files were
shown to be:
backup_feedback.bat
Ln 1 Col 31
46250 ms
46360 ms
With some idea of showing you what happened, I pressed Alt-PrtSc to get a
screenshot of the strange file names. On my machine, I started MS Word and
pasted the contents of the clipboard into my document. The file names were
correct! I tried using Ctrl-PrtSc on the remote machine, but the same thing
happened when I pasted the image into my Word document: the file names were
correct.
I closed the Windows Explorer window and reopened it. And the incorrect file
names reappeared!
Can anybody explain this? Should this be brought to anyone else's attention,
and if so, whose?
RobR
