[Rd] RSQLite indexing

Seth Falcon seth at userprimary.net
Tue Oct 23 06:33:07 CEST 2007


Jeffrey Horner <jeff.horner at vanderbilt.edu> writes:

> Thomas Lumley wrote on 10/22/2007 04:54 PM:
>> I am trying to use RSQLite for storing data and  I need to create indexes on 
>> two variables in the table. It appears from searching the web that the CREATE 
>> INDEX operation in SQLite is relatively slow for large files, and this has been 
>> my experience as well.

What is your schema?  In particular, are things that are integers or
floats being stored that way in SQLite?

I believe the annotation data packages via AnnotationDbi are using
cache_size=64000 and synchronous=0 and that this was determined by a
handful of experiments on typical annotation dbs.

Columns with few levels may not benefit from an index.  See this
thread:

http://thread.gmane.org/gmane.comp.db.sqlite.general/23683/focus=23693

But your column with many levels should suffer this problem :-)

+ seth

-- 
Seth Falcon | seth at userprimary.net | blog: http://userprimary.net/user/



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