I was working on testing some 11g streams configurations today. I needed to startup 3 databases instances on the same server. I was using AMM (Automatic memory management). When i was trying to startup the 3rd database, i kept getting the error message “ORA-00845: MEMORY_TARGET not supported on this system”. I also had error messages in the alert log.
This is because, the space allocated for /dev/shm is not sufficient to allocate the SGA+PGA’s for all the 3 database instances (When using the initialization parameter memory_target). The space allocated needs to be >= the total SGA+PGA size of all the 3 instances together.
You can increase the space allocated using the command “mount -t tmpfs shmfs -o size=2000m /dev/shm” ( I had 3 instances 600mb each SGA+PGA). You can persist this allocation across reboots by adding it to the /etc/fstab.
Today, i ended up having to scan some receipts in, to send my expense reports. I had never tried using printer-scanners with ubuntu ever. But i was pleasantly surprised, by how well, Xsane the linux program for acquiring images with scanners, worked. It worked seamlessly with my HP-Photosmart-C4400 series printer-scanner (Dint have to install any drivers or anything of that sort). You can choose between saving the image as a jpeg or a pdf file.
Once I scanned the images, i ended up with two distinct pdf documents (1 page each), which i had to then combine before i submitted my expense report. I used ghostscript, with the following switches, to combine these two files into a single file.
gs -q -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -sOUTPUTFILE=merged.pdf Tempout-0001.pdf Tempout-0003.pdf
Tempout-0001.pdf and Tempout-0003.pdf are the files I am merging into merged.pdf.
Thought building applications using Microsoft Access was easy ? try building one in Rails, it is Easy…
Install and configure ruby and rails as described in my earlier post.
First create a directory to hold your Rails code. Let us say /u01/ror
Issue the following command to create the necessary rails directory structure
cd to the config directory
Edit the database Connection properties file
Modify the details for the development environment as follows (You can remove test and production). Make sure you use oracle_enhanced as the adapter, and not just oracle.
Create the Model/View and Controller
script/generate scaffold Customer name:string contact:string phone:string email:string
Create the table named Customers in the Oracle database
Start the web server
Then you can access the application you just created by going to your browser and putting in the URL http://localhost:3000/customers.
This application can now view/add/modify/delete customer information
“That was easy”
“Simply Rails 2” by patrick lenz is a great book for Rails beginners and includes Rails 2 information.