c-tree Server V8 Transaction Number Enhancements

For systems that must sustain a high transaction rate, the transaction number limit of the version 6 and version 7 c-tree Server can have significant implications for the availability of the c-tree Server. As an example, a system with a sustained rate of 1000 transactions per second would exceed the 4-byte transaction number limit in about 12 days of continuous operation.

To overcome this limitation, FairCom added support for 6-byte transaction numbers (also known as extended transaction numbers) to version 8 of the c-tree Server. The use of 6-byte transaction numbers (46 bits of which are used for the transaction number) provides the server the ability to sustain a rate of 1000 transactions per second for over 2000 years (as compared to the 12 day limit when using 4-byte transaction numbers).

The V8 c-tree Server always stores transaction numbers in the transaction logs as 6-byte values and stores transaction numbers as either 4-byte or 6-byte numbers depending on the index creation options. All indexes that the server creates for its own internal use are created as 6-byte transaction number indexes, so the only possible source of 4-byte transaction numbers is an application that creates index files as 4-byte transaction number files. If the application creates all its indexes as 6-byte transaction number files, the server will not be subject to the 4-byte transaction number limit.