PostgreSQL 面试题与答案
问题 21. Explain the difference between a stored procedure and a function in PostgreSQL.
Stored procedures are precompiled sets of one or more SQL statements stored in the database, while functions return a value and can be used in SQL queries like any other value.
问题 22. What is the purpose of the COPY command in PostgreSQL?
The COPY command is used to copy data between a file and a table or between tables. It is a high-performance mechanism for bulk data loading.
问题 23. How can you implement full-text search in PostgreSQL?
PostgreSQL provides the tsvector and tsquery data types along with the full-text search functions. To implement full-text search, you can use the tsvector column for indexing and the @@ operator for searching.
问题 24. Explain the purpose of the pg_upgrade utility in PostgreSQL.
The pg_upgrade utility is used to upgrade a PostgreSQL database cluster to a new major version without requiring a full dump and restore. It simplifies the upgrade process.
问题 25. What is a materialized view in PostgreSQL, and when should it be used?
A materialized view is a snapshot of a query result that is stored and can be queried like a table. It should be used when you need to precompute and store the results of a complex query for faster retrieval.
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