Large Instance Points 16th Eurofiling Workshop Wednesday 12 December Herm Fischer Mark V Systems Limited and Arelle open source XBRL processor

Study results RAM consumption vs. instance size Instance XML to DOM (XML only) 1 : 3 to 1 : 10 Instance XBRL to formula processor 1 : 60 Instance XBRL to SAX object model 1 : 15 Conclusion Constant-memory streaming approach suggested Non-XML technologies eventually required

US SEC form SD Mining and oil exploration payout details Sample size: Instance: 21.7 MB Every filer uses extension taxonomy 150,006 facts 21,001 contexts 5 units 0 footnotes

Streaming XBRL in XML syntax Base spec 2.1 working group note (WGN) & task force Compatible organization of instance for streaming SAX vs DOM improves speed, no XML persistence Constant memory usage Use for 2.1 & XDT validation Challenges for Financial validation (~GFM) Formula processing XPath (XML node access)

XBRL streamability issues Order Freedom to order facts, contexts, units, footnotes XML syntax detail Formula & Table Xpath to nodes and XML structure Validation and formula strategies Designed for complete instance in memory Complex fallback and existence strategies

XBRL streaming approach Constant memory Backwards compatibility Order constrained within instances Contexts/units located as needed in instance

Financial Validation EFM/GFM Full object models analysis in memory for Context, unit, fact duplications (could use hashes) Fact cross-dimension analysis (only some concepts) History of concepts used Roll ups, roll forwards, aggregations Full DTS model in memory for Concept issues, label/definition issues Missing / improper calculations, roll-ups, roll-fwds Can be re-architected for streaming environment

Global Ledger Architecture Multiple content models required in parallel Transactions Company data Account data Reformulate for independent streams or persistent company/account models.

Formula Response Define subset of XPath for streamed processor No node-axis features (/ or [ operators) More functions for context, typed dimensions, etc Should allow use of non-XML implementations Define subset of formula processing Consider SQL infrastructures Consider OLAP features Reconsider use of features like Fallbacks Multiple instances of large data sets

Abstract Model Response Abstract model is based on OMG MOF & CWM Abstracted XBRL semantics from syntax Implementation will layer on XML as well as CWM (OLAP supportive technologies) Next step is a pilot project Implement abstract model demonstration Evolve and tweak specs Provide prototype implementation