Why multiple log files are created while using transaction in berkeley db

Question

we are using berkeleydb java edition db base api, we have already read/write CDRFile of 9 lack rows with transaction and
without transaction implementing secondary database concept the issues we are getting are as follows:-
with transaction----------size of database environment 1.63gb which is due to no. of log files created each of 10 mb.
without transaction-------size of database environment 588mb and here only one log file is created which is of 10mb. so we want to know how REASON CONCRETE CONCLUSION ..
how log files are created and what is meant of using transaction and not using transaction in db environment and what are this db files db.001,db.002,_db.003,_db.004,__db.005 and log files like log.0000000001.....plz reply soon

Answer 1

we are using berkeleydb java edition db base api, If you are seeing __db.NNN files in your environment root directory, these are environment's shared region files. And since you see these you are using Berkeley DB Core (with the Java/JNI Base API), not Berkeley DB Java Edition.
with transaction ...
without transaction ...First of all, do you need transactions or not? Review the documentation section called "Why transactions?" in the Berkeley DB Programmer's Reference Guide.
without transaction-------size of database environment 588mb and here only one log file is created which is of 10mb.There should be no logs created when transactions are not used. That single log file has likely remained there from the previous transactional run.
how log files are created and what is meant of using transaction and not using transaction in db environment and what are this db files db.001,db.002,_db.003,_db.004,__db.005 and log files like log.0000000001Have you reviewed the basic documentations references for Berkeley DB Core?
- Berkeley DB Programmer's Reference Guide
in particular sections: The Berkeley DB products, Shared memory regions, Chapter 11. Berkeley DB Transactional Data Store Applications, Chapter 17. The Logging Subsystem.
- Getting Started with Berkeley DB (Java API Guide) and Getting Started with Berkeley DB Transaction Processing (Java API Guide).
If so, you would have had the answers to these questions; the __db.NNN files are the environment shared region files needed by the environment's subsystems (transaction, locking, logging, memory pool buffer, mutexes), and the log.MMMMMMMMMM are the log files needed for recoverability and created when running with transactions.
--Andrei