Large database

[Steve]

I want to create a large database/global of the form -- ^Global(Sub1,Ctr)=Value -- with 300,000,000 entries in it initially.

Is there anything special I need to do for GT.M to be able to handle this?

Thanks, Steve

[OldMster]

Other than to make sure you have sufficient disk space to hold it, nothing I can think of.
Mark

[Sam Habiel]

On Wednesday, June 15, 2016 at 2:14:27 PM UTC-4, Steve wrote:

Bhaskar will chime in soon; I think the limit for a single database *file system file* in GT.M is 4 TB. You can split your global across database files if it gets too big, so you can have effectively infinite storage.

[K.S. Bhaskar]

Sam is a good astrologer - he can predict my behavior!

Steve, 300,000 nodes is nothing for a GT.M global - there are databases in production with orders of magnitude more entries than that. There is no inherent limit to the number of nodes in a database file.

It is important to make the distinction between a database and a database file. As a database file has a size limit of 992Mi blocks, if you use a 4KiB block size (the most popular block size), the maximum that a database file can grow to is 3968GiB, which is around 4TB. A database can be composed of / distributed over an arbitrarily large number of database files (there is a limit - I remember something like 2**32 database files per database, though I haven't checked recently - but I doubt that anyone will reach that in our lifetimes).

So, as Mark notes, the only practical limit is the amount of available storage.

If you are planning to build a large database, let me suggest going through the GT.M Acculturation Workshop. Go to https://sourceforge.net/projects/fis-gtm/files/GT.M%20Acculturation%20Workshop/ and get the latest version (0.9 as of today). It consists of a series of self-paced exercises that you execute using a virtual machine (provided, if you don't have one already).

Regards
-- Bhaskar

[Steve]

Thanks all for your suggestions.