Chapter 4.  Access Method Wrapup

Table of Contents

Data alignment
Retrieving and updating records in bulk
Bulk retrieval
Bulk updates
Bulk deletes
Partial record storage and retrieval
Storing C/C++ structures/objects
Retrieved key/data permanence for C/C++
Error support
Cursor stability
Database limits
Disk space requirements
External File support
The external file threshold
Creating external files
External file access
External file storage
External Files and Replication
Access method tuning
Access method FAQ

Data alignment

The Berkeley DB access methods provide no guarantees about byte alignment for returned key/data pairs, or callback functions which take DBT references as arguments, and applications are responsible for arranging any necessary alignment. The DB_DBT_MALLOC, DB_DBT_REALLOC, and DB_DBT_USERMEM flags may be used to store returned items in memory of arbitrary alignment.