It has been a couple of years since I posted statistics from WorldCat, so here is a new spreadsheet (link updated Dec 14 2009. There were errors in the previous spreadsheet) based on an October 1, 2009 snapshot (see the earlier post for an explanation of the table). WorldCat has changed dramatically since March 2007, going from 83 million records to nearly 146 million. A few other changes for those that might be interested:
- Holdings went from 1.12 billion to 1.47 billion
- Average record length decreased from 803 bytes to 784 bytes
- Fields/record also declined from 15.4 to 14.9
In case you are tempted to think the decline in record length heralds a trend towards bibliographic simplicity, you may be as startled as I was to see the number of different MARC subfields almost double from 1,670 to 3,278! I doubt if that has ever happened in 36 months before. Even the addition of 63 million records doesn't explain it (although the amount of non-US cataloging added might).
Please remember that these statistics reflect only the cataloging database, not all the records visible at http://www.worldcat.org, which is much larger because of the inclusion of all the abstracting and indexing databases it loads.