In order to downgrade an 11.2.0.3 Enterprise Edition database to Standard Edition, I had to use a Transportable Tablespace export/import. Because the default setting for DEFERRED_SEGMENT_CREATION is TRUE, the tablespace import barfed with numerous “IMP-00017: following statements failed with ORACLE error 1647:” errors. Want to know why? The ORA-01649 error is “Tablespace is read only, cannnot allocate space in it” which is interesting as I’m importing a Transportable Tablespace dump file and all the tablespaces are read only after being created, until I manually make then read write.

Ever wanted to backup your Raspberry Pi’s SD card, but didn’t know who to ask? Me too. Read on …. The first thing to remember is that you should really always have a backup of your SD card. In theory every time you make a change, but in practice, it will be less frequently than that! I have had two cards corrupt themselves when I managed to lock my Pi completely, and the only recourse was to pull the power.

Update: 23/02/2023: The following link no longer exists. Some people are confused by the clustering factor of an index in an Oracle database. Be confused no more, just read this article by Tom Kyte on the subject.

Want to know how to redirect the sound from your Pi to either the HDMI or to the headphone socket? Read on … Update - 11 February 2013 I’ve written a small command line utility - PiSound - to control the settings of the audio device on your RaspberryPi. You can download it from https://github.com/NormanDunbar/PiSound. Enjoy. Deciding on the Output Device The following command is all you need: 1 sudo amixer cset numid=3 n Where the final ’n’ is as follows:

And while you are at it, no warranty problems when you do so! An announcement on the Raspberry Pi Foundation web site, read it here, (Update: 23/02/2023: Sorry, dead link now.) explains that it is now possible to use Turbo mode on your Raspberry Pi without invalidating your warranty by over volting the device. Please go and read it and then pop back here for instructions on adding Turbo mode to your own Raspberry Pi.

Brilliant! Read Tony Ballantyne’s excellent article. And enjoy.

As a Raspberry Pi user, I figured I needed a USB hub to allow me to connect stuff (that’s a technical term by the way) to my Pi without overloading the two on board USB ports as these are limited to a maximum of 100 mA each. I purchased a cheap 7 port externally powered hub and it arrived by next day delivery. The USB 2.0 specification says that anything advertising compliance should, amongst other things be able to supply 500 mA minimum on each and every port while externally powered and should not feed any power back to the computer via the USB interconnect cable - that’s the one between the computer and the hub.

Adrci is a new tool in Oracle 11g which makes life a little easier when gathering evidence to send off to Oracle Support, but it can make life easier when you simply wish to view the alert log, for example. As ever, you need to be logged in to the database server and have the environment set in the normal oraenv manner. This is how we used to do it in the old, pre 11g, days:

Installing Oracle Multimedia, which is required for Spatial and/or Locator is quite simple. All of the following must be carried out while logged in as a SYSDBA user. 1 2 3 4 5 6 7 8 9 10 11 SQL> spool ordinst.log SQL> @?/ord/admin/ordinst SYSAUX SYSAUX ... ... SQL> spool off SQL> spool catim.log SQL> @?/ord/im/admin/catim ... ... SQL> spool off Lots of stuff will scroll up the screen but will also be copied to the spool files named.

So, you renamed your database using the nid utility as outlined here but now you need (or want) to change all the file system names to suit. Read on. In the following example, we have two mount points for the database. Files on these mounts are spread all over a pile of separate discs making up the LUN - so it’s not as bad as it looks! The two mounts are wrongly named at the moment since we changed the database name using nid and we would like to tidy things up.

As you already know, an Oracle database’s PMON process will register your database with a listener without you having to do anything about it. However … This will only happen if the listener in question is running on port 1521. And it doesn’t have to be named LISTENER either – as I mistakenly thought– it only has to be port 1521. If you have a listener running on port 1521, and you have databases configured to connect via different listeners on other ports (on the same server) then your databases will be grabbed by the 1521 listener!

It was my own fault, but in case it proves even slightly useful…. I was upgrading from 11202 to 11203 Enterprise using the DB Upgrade Assistant utility. When I said ‘go do it’ it went off, chugged for a bit, then barfed. DBUA informed me that the database wasn’t running. I checked, it was. Cutting a long story short, I checked the indicated logfile and discovered that DBUA had connected to the database but then got a couple of errors telling it that ‘oracle was not available’.

Locator is “Spatial Lite” if you wish, and costs nothing. It can be installed in Standard or Enterprise Editions with no additional licensing costs. You cannot do everything in Locator that you can in Spatial - but what do you expect for free? ;-) To install Locator you need to be aware that things changed at 11g, so what used to work on 10g no longer does on 11g and can lead to you having a huge mess of objects and types to hunt down and remove from your SYS account - ask me how I know!