Hi,
We've encountered what we think is an odd situation and we can't find
any explanation for why this is. We're also not sure if its a problem or
not.
A brief summary is that we are doing a major database upgrade and are
doing (lots) of testing. The box is a Linux box running Ubuntu 14.04 LTS
Server. This is a standard box we have used for a few years, we *might*
move to 16 LTS shortly.
As part of the testing we noticed that -shm and -wal files were being
left after we used sqlite3 on the command line. This puzzled us as we
didn't see any errors in our test scripts.
We then narrowed this problem down to doing a simple SELECT statement on
a table.
e.g. This is our starting state. Note that nothing is touching these
database as they are isolated in a directory, so there is no other
process playing with them.
root@demonotifications:/jambuster/notifications/upgrade_test# ls -lt
total 66892
-rw-r--r-- 1 root root 34217984 May 15 10:38 accountmanagement.sqlite
-rw-r--r-- 1 root root 58567 May 15 10:31 upgradedb.sql
-rw-r--r-- 1 root root 34217984 May 13 20:38
accountmanagement.sqlite.orig
root@demonotifications:/jambuster/notifications/upgrade_test# cp
accountmanagement.sqlite.orig accountmanagement.sqlite
root@demonotifications:/jambuster/notifications/upgrade_test# sqlite3
accountmanagement.sqlite
-- Loading resources from /root/.sqliterc
SQLite version 3.8.2 2013-12-06 14:53:30
Enter ".help" for instructions
Enter SQL statements terminated with a ";"
sqlite> select * from device;
UUID isValid Version
WhatAmI Application
--------------------------------------------------- ----------
---------- ---------- ------------------
<<REDACTED> 1 1.1
ios_app JambusterForLondon
...... Hundreds more lines of device data which looks correct
<<REDACTED> 1 1.1
ios_app JambusterForLondon
sqlite> .exit
root@demonotifications:/jambuster/notifications/upgrade_test# ls -lt
total 66924
-rw-r--r-- 1 root root 32768 May 15 10:48
accountmanagement.sqlite-shm
-rw-r--r-- 1 root root 0 May 15 10:48
accountmanagement.sqlite-wal
-rw-r--r-- 1 root root 34217984 May 15 10:47 accountmanagement.sqlite
-rw-r--r-- 1 root root 58567 May 15 10:31 upgradedb.sql
-rw-r--r-- 1 root root 34217984 May 13 20:38
accountmanagement.sqlite.orig
root@demonotifications:/jambuster/notifications/upgrade_test
As can be seen above, we have accountmanagement.sqlite-shm and
accountmanagement.sqlite-wal files left which is odd. All of this from a
select statement.
If we do an pragma integrity check we get
integrity_check
---------------
ok
All the reading we have done seems to indicate that having -shm and -wal
files indicates an error, if this was our code, we'd be looking deep
into that but a simple select statement shouldn't cause this sort or
error, can it?
The select statement has a number of foreign key delete cascades but
thats it, and as we are not deleting anything this shouldn't be an issue
anyway.
Do we even have a problem? Going back into the database and closing it
again, just with the command line utility sqlite3 doesn't clear the
files.
Any help or suggestions welcomed.
Thanks
Rob
_______________________________________________
sqlite-users mailing list
sqlite-users@mailinglists.sqlite.org
http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
