Dear Yuvi, I do not think that getting the data in sqlite format is going to be very valuable. People can already get the data in Mysql databases (although that is not that easy either) and so getting it in sqlite will not give additional benefits in terms of querying capabilities. I am also not sure if sqlite can handle such large databases. What I do think might be valuable is to work on a text format (JSON, CSV) to store the dumps. The reason is that we are looking at a Nosql datastore solution (for example Hadoop) and storing the data in a non-xml but still text format is going to be really useful. Just my 2 cents. Best, Diederik On 2011-03-28, at 6:10 PM, Yuvi Panda wrote:

On 2011-03-29, at 10:45 AM, Yuvi Panda wrote: Basically you are going to develop a sharding solution using sqlite. I think you are overstretching the use case of sqlite (IMHO). When each revision is on a separate row it will be way easier to run map/reduce jobs else you have to figure out where a revision starts and ends, and each row should contain all variables (IMHO)

Hi there, I am using the Wiki dumps for work, and I have been following this list for some time now. Since you bring it in, I do think too that "the simpler the better" regarding data formats for batch-processing with Hadoop. Working with table-like data formats is easy as this is the default format. Working with XML, JSON and other formats allowing complex nested structures (e.g. map, lists, and combination of them) is slightly more difficult as it involves serialization/de-serializations steps for which libraries need to be available for your favorite framework: Hadoop Java M/R, Hadoop Streaming, Pig, Hive, etc. Nothing very difficult though... I am glad to see some thinking around Hadoop (and NoSQL) as this the way to go when working with large datasets such as Wikipedia. Best, Nicolas Torzec. On 3/29/11 7:45 AM, "Yuvi Panda" <yuvipanda(a)gmail.com> wrote: Heya Diederik, On Tue, Mar 29, 2011 at 7:58 PM, Diederik van Liere <dvanliere(a)gmail.com> wrote: True, but it's not one large sqlite database - it'll be split across multiple smaller ones, and explicit pointers will be maintained so that random access is as effecient as possible. Interesting. How exactly would having JSON/CSV be better than XML from a import-into-nosql-datastore perspective? \ -- Yuvi Panda T http://yuvi.in _______________________________________________ Xmldatadumps-l mailing list Xmldatadumps-l(a)lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/xmldatadumps-l

I have a PHP script (that runs on command line) that pretty much does that... it generates an XML index file with the following entry for each identified page from the XML dump: <page id="%d" revision="%d" datetime="%s" length="%d" start="%d" end="%d" title="%s" /> Where id = page id revision = revision id datetime = revision date/time length = length of the revision <text> XML entity CDATA start = line number of the <page> entity end = line number of the </page> entity title = page title Example of first three entries: <page id="10" revision="381202555" datetime="2010-08-26T22:38:36Z" length="57" start="32" end="47" title="AccessibleComputing" /> <page id="12" revision="408067712" datetime="2011-01-15T19:28:25Z" length="96718" start="48" end="453" title="Anarchism" /> <page id="13" revision="74466652" datetime="2006-09-08T04:15:52Z" length="57" start="454" end="468" title="AfghanistanHistory" /> If this is of any use to anyone, I can put it up... -- James