Create New Database

The CHCREATE GX is run from within the CHIMPORT GX and CHIMPLAB GX to create a new database file.

Create New Database dialog options

New database name

The name of the new database (.gdb assumed)

Maximum soil survey lines

 

 

 

Maximum fields/channels

Maximum number of lines or groups that the new database can contain and the maximum number of channels or fields. These values should be set to about 50% more than you expect to use.

The database uses a static index which will be as large as the product of these two numbers (times 6 bytes). A static index provides you with a maximum of performance in processing your data, and the index can be as large as reasonably required for your project. The size of the index only affects the time it takes to open and close a database. Once a database is open, data processing performance is not affected in any noticeable way by the size of the database index. Note that the size of the index is not related to the volume of data that can be stored in the database.

Once a database is created with a certain index size, attempting to add lines/groups of channels/fields above the maximum values specified here will cause an error. If this happens you must grow the size of the index using Data|Maintenance|Grow… option from the main menu.

Compression

Specify the compression requirements for the database. There are three compression options available:

  1. No compression. This is the default compression and is appropriate for databases less than about 10 Megabytes. You should also use this option if your databases must be compatible with Oasis montaj 4.2, service pack 6. Data compression is only supported in version 4.3 and later.

  2. Compress for speed. This uses a very fast compression technique that can reduce the database size by up to 55% and improve data access performance by up to 23%. Performance improvements result from the CPU speed of modern computers being significantly better that the performance of reading/writing data to disk. Performance results will vary depending on your hardware.

  3. Compress for size. This uses a slower compression technique that can reduce database size by up to 80% at the cost of up to 20% increase processing time. Note that performance will depend a great deal on the ratio of performance between your disk and CPU and will vary among computers. Use this option for very large databases (> 100 Megabytes).

Advanced

This will display more advanced database options in a separate dialog.

Create New Database (Advanced Parameters)

This dialog allows you to change the way Oasis montaj works with data in the database file. These parameters control the database "page size", which is the smallest unit of memory that is read/written and stored on the database. In almost all cases, the default page size (1024 bytes) should be sufficient since this will support a total database size of up to 4 Terabytes in size and will allow individual channels on a line to hold up to 64 Megabytes of data.

If your data requirements will be larger than this, you can specify your requirements here. A page size will be chosen to be large enough to support your needs. The largest page size supported is 16384 bytes, which will allow databases up to 64 Terabytes (64,000,000,000,000 bytes), and individual channels to hold up to 1 Gigabyte of data.

Note that larger page sizes are only appropriate for very large data sets where you will be processing large data streams. If you use a large page size for small data sets, you will consume unneeded disk space and reduce the performance of reading and writing your data.