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The Unified Medical Language System regularly releases a set of terminologies in a large set of files referred to as the UMLS Metathesaurus.  LexEVS can load individual files from this file set using the LexEVS RRF loader also known as the LexEVS UMLS Batch loader, due it it's memory optimization capabilities.  We briefly mention the UMLS Metathesaurus tools on this page.  Since all documentation for these is maintained at the website linked to below we don't repeat it here.  As well LexEVS has a special purpose RRF loader which loads an NCI version of an entire MetaThesaurus. 

If you load larger ontologies, we recommend use of the command line options, this will allow manipulation of the memory allocated for loads of larger terminologies such as SNOMED. Scripting options can be added to the scripts contained at <LexEVS install base>/gui.  If a user is working on a Linux environment with a 64 bit architecture, then they can use the Linux_64-lbGUI.sh file.  On a server class computer with say 16  gigabytes of memory and 8 four core processors users can access fairly substantial resources to load content.   Open the .sh file with a text editor and edit the values for -Xmx and -XX:MaxPermSize as follows "-Xmx6000M -XX:MaxPermSize=256M"  or more if you have resources available. At this setting it could still take about 33 hours to load a terminology as large as SNOMED. 

1

Install Metathesaurus to a local folder:
Loading from these sources requires that the UMLS Metathesaurus be installed locally so it can be accessed from LexEVS.  This can be done according to documentation available on the UMLS website.  

2

Subset the desired terminology (optional):
Once the Metathesaurus is downloaded and installed, users can either load from the entire set of files by pointing to the containing file directory or they can use the UMLS tools to subset a terminology (recommended).  Subsetting the terminology beforehand provides improved performance during loads.

3

Set command line options in the loading script:
If you load larger ontologies, we recommend use of the command line options, this will allow manipulation of the memory allocated for loads of larger terminologies such as SNOMED. Scripting options can be added to the scripts contained at <LexEVS install base>/gui.  If a user is working on a Linux environment with a 64 bit architecture, then they can use the Linux_64-lbGUI.sh file.  On a server class computer with say 16  gigabytes of memory and 8 four core processors users can access fairly substantial resources to load content.   Open the .sh file with a text editor and edit the values for -Xmx and -XX:MaxPermSize as follows "-Xmx6000M -XX:MaxPermSize=256M"  or more if you have resources available. At this setting it could still take about 33 hours to load a terminology as large as SNOMED. 

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