From the objective of OSS-DB Exam Gold
- Advanced Server Administration - Database architecture
Sample Question
1.11
Select all the statements that are accurate regarding the process architecture of PostgreSQL.
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A separate server process is spawned for each client connection to the database.
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A separate server process is started for each database within the database cluster.
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Several processes are running, including the WAL writer, autovacuum launcher, and statistics collector; all are created from the same "postgres" executable.
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When no clients are connected, typically only the "postmaster" process is running.
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A single "postmaster" process is running for each database cluster.
※This sample exam is different from those that appear in the actual OSS-DB Exam.
2025/05/29
Answer and Explanation
PostgreSQL employs a multi-process architecture, where each database cluster is managed by a process called postmaster.
When running multiple database clusters on a single server, there is one postmaster process for each database cluster.
Each database cluster has several postgres processes running, including the writer, wal writer, autovacuum launcher, stats collector, among others. Although these processes have different functions, they are all created from the same executable file, postgres (or postgres.exe on Windows).
These processes run even when no clients are connected to the database.
When a client connects to the server, a corresponding postgres process is launched to handle database access operations.
Therefore, the correct answers are A, C, and E.