Resolve the internal structure of the database application architecture

Database internal structure

All information in the adaptive Server Anywhere database is typically stored in a single database file and can be replicated from one computer to another. You can also generate databases for several files, but typically only a very large database needs to do so.

In addition to the database files, adaptive Server Anywhere uses two additional files when it runs the database. These two files are transaction logs and temporary files.

Database files

Internally, the database file is made up of pages (a fixed size area of the disk). The data access layer reads and writes data on one page at a time. Many pages hold data from a database table, while others save index information, information about the distribution of data within the database, and so on.

Transaction log

The transaction log is a separate file that records all operations performed on the database. Typically, it has the same name as the database file, except that it ends with the suffix. Log instead of. db. The transaction log has three important features.

• Record actions performed on data to support recovery if the database file is corrupted, you can re-create the database based on the backup and the transaction log.

• Improve performance by writing information to the transaction log, the database server can safely process your statements without having to write frequently to the database files.

Support for database replication

SQL remote and the Mobilink client utility Use this file to copy changes to a database on a portable computer that is sometimes connected to a network.

The temporary file opens when the database server starts, and the temporary file closes at the end of the database server. As the name suggests, temporary files are used to hold temporary information while the server is running. Temporary files do not save information that needs to be retained between sessions.

The temporary file is stored in your temporary directory. The location of this directory is usually identified by the TEMP environment variable.