How Can I Implement Per-Primary Key Auto-Incrementing Indexes in SQL and NoSQL Databases?

Handling Per-Primary Key Auto-Increment Indexes

The goal is to implement an auto-increment mechanism that generates distinct auto-increment indexes for each primary key value.

SQL Engine Support

• MySQL (MyISAM Engine): Supports this functionality through the AUTO_INCREMENT keyword on secondary columns in multi-column indexes.

Alternative Solutions

If the native SQL engine does not support this feature, alternative approaches include:

• Triggers: Emulation using triggers requires table locking to prevent race conditions.
• Database Programming: Create a custom incrementer using a database procedure or function.

Suitable Name

This functionality could be referred to as Partitioned Auto-Incrementing, Scope-Bound Auto-Incrementing, or Per-Category Auto-Incrementing.

Non-SQL Database Support

• MongoDB: Offers support for partitioned auto-incrementing using an options field in its document structure.

Implementation Considerations

• Lock handling: Locking the entire table may be necessary to prevent race conditions when using triggers.
• Transaction behavior: Non-transactional approaches ensure uniqueness but not consecutive values within the same scope.
• Data consistency: Deleted rows may cause gaps in the auto-increment sequence, especially in the case of renumbering.

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