Efficient Paging in SQLServer Optimizing your Query Performance（sqlserver分页）

Paging is a common operation used in many database applications. It allows an application to retrieve a specific subset of data from a large data set. Utilizing efficient paging in SQLServer can help you optimize your query performance and improve the overall user experience.

SQL Server has several built-in features that provide efficient paging. The core of these features is the OFFSET and FETCH clauses. The OFFSET clause allows you to define the start row of your query, while the FETCH clause allows you to define the number of rows to return. This combination of clauses allows you to easily implement efficient querying on large data sets.

The following query statement using the OFFSET and FETCH clauses provides long-term scalability and performance for a paginated application. It returns rows starting from the fifth row and returning a maximum of five rows.

SELECT
   col1, col2, col3 
FROM
    myTable
ORDER BY
    col1
OFFSET 5 ROWS
FETCH NEXT 5 ROWS ONLY

In addition to the OFFSET and FETCH clauses, SQL Server provides several other features to help you optimize your queries for efficient paging. One of these features is the ROW_NUMBER() window function. This allows you to assign a unique number to each row in the result set. This can help you eliminate duplicate rows, as well as specify which rows should be returned in the query.

The following query statement uses the ROW_NUMBER() window function to paginate the result set. This statement returns rows with a row number between 11 and 15.

“`

SELECT

col1, col2, col3

FROM

(SELECT

ROW_NUMBER() OVER (ORDER BY col1) AS RowNumber,

col1, col2, col3

FROM

myTable) AS MyTable

WHERE

RowNumber BETWEEN 11 AND 15

Finally, SQL Server also provides another feature to help you optimize your queries. This is the ROWS BETWEEN UNBOUNDED PRECEDING and CURRENT ROW window frames. This frame clause allows you to specify a set of rows that should be returned in the query result. This can help you more quickly access the desired data. 

The following query statement uses the ROWS BETWEEN UNBOUNDED PRECEDING and CURRENT ROW window frames to paginate the result set. This statement returns the first ten rows in the data set. 

SELECT

col1, col2, col3

FROM

(SELECT

ROW_NUMBER() OVER (ORDER BY col1) AS RowNumber,

col1, col2, col3

FROM

myTable) AS MyTable

WHERE

RowNumber BETWEEN UNBOUNDED PRECEDING AND 10 FOLLOWING

SQL Server provides several built-in features to help you efficiently paginate your data sets. Utilizing these features can improve the performance of your queries, while also providing long-term scalability and reliability. Experiment with these features, and see how they can help you optimize your query performance.