- Grammatical Analysis
- “CREATE” is a verb in the imperative mood. In the context of database operations, it is used to issue a command. Imperative verbs are commonly used in SQL (Structured Query Language) commands to tell the database management system what action to perform. Here, “CREATE” indicates the intention to make or establish something new.
- “SYNONYMS” is a plural noun. It refers to alternative names for database objects such as tables, views, procedures, etc. A synonym provides an additional way to reference a database object, which can be useful for simplifying object access, especially in complex database environments.
- Function and Usage in Databases
- Purpose of Creating Synonyms
- Simplification of Object References: In a large database, objects may have long or complex names. For example, in an enterprise - level database, a table might be named “HR_DEPARTMENT_EMPLOYEE_RECORDS_2025_Q1”. Creating a synonym like “EMP_RECS” for this table allows users to access the table with a much shorter and more convenient name. This simplifies SQL statements, making them easier to write and understand. For instance, instead of writing “SELECT * FROM HR_DEPARTMENT_EMPLOYEE_RECORDS_2025_Q1;”, a user can write “SELECT * FROM EMP_RECS;”.
- Abstraction and Data Hiding: Synonyms can be used to abstract the actual location or structure of a database object. Suppose a table is moved from one schema to another or its name is changed for some reason. By using a synonym, the applications that access the table through the synonym do not need to be modified. The synonym acts as an indirection layer. For example, if a view was initially created in schema “A” and is later moved to schema “B”, as long as the synonym is updated to point to the new location of the view, the queries that use the synonym will continue to work without any changes to the application code.
- Syntax Variations
- In different database management systems, the syntax for creating synonyms may vary slightly. For example, in Oracle, the basic syntax is “CREATE [PUBLIC] SYNONYM synonym_name FOR object_name;”. The “PUBLIC” keyword is optional. If “PUBLIC” is specified, the synonym is available to all users in the database. In SQL Server, the syntax is “CREATE SYNONYM [schema_name.]synonym_name FOR [server_name].[database_name].[schema_name].object_name;”. Here, more details about the object's location (server, database, and schema) are required, especially when referring to objects in remote databases or different schemas.
- Purpose of Creating Synonyms
- Benefits and Considerations
- Benefits
- Enhanced Portability: When migrating a database or parts of it, synonyms can help in maintaining the integrity of the application's access to database objects. If the actual object names or locations change during the migration, the synonyms can be adjusted, and the application can continue to function as expected.
- Security and Role - Based Access: Synonyms can be used to control access to database objects. For example, a user may be granted access to a synonym but not to the actual underlying object. This allows for a more fine - grained control of permissions. A junior developer might be given access to a synonym that provides a limited view of a table's data, while the full table access is restricted to more senior developers or administrators.
- Considerations
- Maintenance: As synonyms are additional database objects, they need to be maintained. If an underlying object is dropped, the synonym becomes invalid. Database administrators need to ensure that synonyms are updated or dropped when the relevant objects are modified. For example, if a table is renamed, the synonym that references it must be updated to point to the new table name.
- Performance: In some cases, using too many synonyms or complex synonym chains can potentially impact performance. When a query is executed using a synonym, the database management system needs to resolve the synonym to the actual object. If this process involves multiple levels of indirection or complex resolution algorithms, it may add some overhead to the query execution time.
- Benefits
Create synonym,synonyms of create
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