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Support Forums => MP Server => Topic started by: app4pzb on January 05, 2009, 11:14:36 AM

Title: Identify documents using large object support
Post by: app4pzb on January 05, 2009, 11:14:36 AM

We have an application which implements large object support breaking at 100 pages and would like to know which individual documents are being broken into multiple pieces.  I can see "Large Object:  No" or "Large Object:  Yes" in the thick client under properties but do not see a way to get this information from the DB2 application group table (i.e. AAA#).  Also, is there any way to derive the length of the entire document.  The DOC_LEN field for an object that is split up holds a very small value (probably corresponding to the size of the first 100 pages).

thanks,

Paul
pbacinsky@ups.com

Title: Re: Identify documents using large object support
Post by: Justin Derrick on January 06, 2009, 08:37:22 AM

Large Object Support is facilitated by removing some of the index information from DB2, and putting it into a header that's stored with the object itself.  I've run into this before while trying to estimate the volume of storage required to do a data extraction.  I'm not aware of any published specification for that header, so there's no quick and easy solution.

There ARE ways of getting this data if it's absolutely critical -- but your best bet going forward is to enable page counting in one of the more recent versions of CMOD, so that the number of pages is a value in a DB2 field.

-JD.

Title: Re: Identify documents using large object support
Post by: app4pzb on January 07, 2009, 07:23:48 AM

Justin,

Thanks for your response.  I figured you'd have some insight into this.  "There ARE ways of getting this data if it's absolutely critical". 

I'll bite.  What's the pain I'll have to endure to find this out?  We have a unique situation where analysis of this historical data is critical for a recently implemented production application.

thanks,

Paul

Title: Re: Identify documents using large object support
Post by: app4pzb on January 09, 2009, 01:21:55 PM

Justin,

not the most elegant work around but i found that unload to a generic index file will identify documents stored as large objects.

p

Title: Re: Identify documents using large object support
Post by: Justin Derrick on January 10, 2009, 09:38:57 AM

You read my mind....

I have a high-speed extractor that would assist in getting you the data you need in as short a time as possible.  Let's talk about that offline.

-JD.

Title: Re: Identify documents using large object support
Post by: app4pzb on January 21, 2009, 08:38:08 AM

for the benefit of the forum we received a response from IBM after they contacted development.  the DOC_NAME field on the application group has a '$' to the end for large objects.  The doc_len value for  large object is the length of the header for that particular large object.  this header contains the offsets and lengths for all the segments in the large object.  i've confirmed in our db2 tables.

paul