Overview | Benefits | Creation | Portability | Scalability
Omnidex Snapshots are extremely easy to move around as they are simply a collection of files. They can be backed up, moved to other servers, or if allowed, transferred to an analyst's laptop.
There are three groups of files associated with an Omnidex Snapshot:
The Omnidex Environment File contains all the metadata describing the Omnidex Snapshot.
./simple.xml
The data files often reside in a single directory, but can be spread to different locations as determined by the Omnidex Administrator.
./dat/cnt.dat ./dat/gdr.dat ./dat/households.dat ./dat/individuals.dat ./dat/sta.dat
The index files are located in a single directory as declared in the Omnidex Environment File
./idx/SIMPLE0000 ./idx/SIMPLE0001 ./idx/SIMPLE0002 ./idx/SIMPLE0003 ./idx/SIMPLE0004 ./idx/SIMPLE0005 ./idx/SIMPLE0006 ./idx/SIMPLE0007 ./idx/SIMPLE0008 ./idx/SIMPLE0009 ./idx/SIMPLE0010 ./idx/SIMPLE0011 ./idx/SIMPLESTATS
Copying an Omnidex Snapshot is as simple as copying the files of the snapshot. The only precaution necessary is to make sure the files are not being accessed by any other processes.
Note that it is generally required that the target server use the same version of Omnidex as the source server. If the Omnidex versions are different, it is usually required to regenerate the Omnidex Environment File and regenerate the Omnidex Indexing.
Omnidex Environment Files will reference directories and filenames. The CREATE DATABASE statement will declare the Index Directory. The CREATE TABLE statements will declare the physical filename(s) for the the table. These statements can contain either absolute or relative filenames.
An absolute filename is one where the path is fully declared, including drive or volume information, plus any directory or subdirectory information. A relative filename is on that is relative to the “current working directory”. With Omnidex, the “current working directory” is the directory containing the Omnidex Environment File.
It is generally easier to move Omnidex Snapshots that use relative filenames. In this situation, you can copy the directory containing the Omnidex Environment File, plus all of its subdirectories. At the same time, performance or space requirements may make relative filenames impractical. Files may need to be moved to other volumes or drives in order to achieve good I/O performance or to obtain enough disk space. In these cases, environment variables can provide a similar flexibility.