Hi there

My customer has a requirement to store 64 billion records.
I am looking for hard figures on size limits for BDB.
I would also be interested in actual testimonies as well as
theoretical limits.

- What is the limit on database file size ?
- Is anything special needed at compile time to support this limit or
is it a runtime confi matter ?
- What is the limit on number of records in Btree tables ?
- BTree databases with RECNUM support are limited to 4 billion
records. Is it a big job to widen the size of this field to support
bigger tables ?

Thanks
Chad.

chadzakary (AT) hotmail (DOT) com (Chad) wrote in message news:<a4e918e3.0309180312.6de8a5ad (AT) posting (DOT) google.com>...

For this information, see the "Database limits" section of the
Berkeley DB Reference Guide, included in your download package
and also available at:

http://www.sleepycat.com/docs/ref/am_misc/dbsizes.html

Using the maximum database page size of 65536, Berkeley DB has
a maximum database file size of 2^48 (256 terabytes). The
minimum database page size is 512 bytes, which results in a
minimum maximum database size of 2^41 (2 terabytes).

No special support is needed at compile time.

There is no limit, unless the records need to be accessed by
record number instead of by key.

It would not be a simple change. Specifically, the change would
change Berkeley DB's on-disk page format, which would potentially
impact the database transaction recovery code.

Regards,
--keith

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Keith Bostic bostic (AT) sleepycat (DOT) com
Sleepycat Software Inc. keithbosticim (ymsgid)
118 Tower Rd. +1-781-259-3139
Lincoln, MA 01773 http://www.sleepycat.com

Thanks Keith

I understand the file format changes, but in what way is the
transaction recovery code affected ?

Chad

chadzakary (AT) hotmail (DOT) com (Chad) wrote in message news:<a4e918e3.0309220326.7285755f (AT) posting (DOT) google.com>...
Berkeley DB does physical logging, and so page format changes will
usually require new log records and recovery code changes as well.

Regards,
--keith

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Keith Bostic bostic (AT) sleepycat (DOT) com
Sleepycat Software Inc. keithbosticim (ymsgid)
118 Tower Rd. +1-781-259-3139
Lincoln, MA 01773 http://www.sleepycat.com