Information Schema
Information Schema is a standardized set of read-only views in relational database management systems (RDBMS) that provide metadata about database objects such as tables, columns, indexes, and privileges. It is defined by the SQL standard (ISO/IEC 9075) and implemented in many databases like MySQL, PostgreSQL, and SQL Server to allow querying of system information using SQL. This schema serves as a catalog or dictionary that describes the structure and properties of the database.
Developers should learn and use Information Schema when they need to programmatically inspect database metadata, such as for database administration, generating dynamic SQL queries, or building tools that require schema discovery. It is particularly useful in scenarios like database migration, auditing, or when writing applications that adapt to changing database structures without hardcoding schema details. By using standardized SQL queries, it ensures portability across different database systems that support the standard.