SQL Traversal Analysis
In SQL stored procedures and functions, traversal (traversal of tables) is often used, among which traversal methods such as cursors and temporary tables are commonly used. In the face of a small amount of data, these traversal methods are feasible, but when faced with a large amount of data, it is necessary to choose the best choice. Different traversal methods have exponential differences in efficiency.
This article lists three commonly used traversal methods: cursors, temporary tables, and index tables, focusing on analyzing their efficiency.
This article is mainly aimed at the traversal of a large amount of data, when the amount of data is small; you can choose a traversal method at will.
The instance data is as follows: a total of 177471 pieces of data
1. Cursor traversal
traversal of the cursor
2.
22
3.
33