C#中如何监控数据库的索引碎片？如何重新组织索引？

using System;
using System.Data.SqlClient;

public void CheckIndexFragmentation()
{
    string connectionString = "your_connection_string_here";
    string query = @"
        SELECT 
            OBJECT_NAME(ps.object_id) AS TableName,
            i.name AS IndexName,
            ps.index_type_desc,
            ps.avg_fragmentation_in_percent,
            ps.page_count
        FROM sys.dm_db_index_physical_stats(DB_ID(), NULL, NULL, NULL, 'LIMITED') ps
        INNER JOIN sys.indexes i ON ps.object_id = i.object_id AND ps.index_id = i.index_id
        WHERE ps.database_id = DB_ID()
          AND ps.avg_fragmentation_in_percent > 10
          AND ps.page_count > 8  -- 至少一个extent的数据
        ORDER BY ps.avg_fragmentation_in_percent DESC";

    using (SqlConnection conn = new SqlConnection(connectionString))
    {
        conn.Open();
        using (SqlCommand cmd = new SqlCommand(query, conn))
        {
            using (SqlDataReader reader = cmd.ExecuteReader())
            {
                while (reader.Read())
                {
                    Console.WriteLine($"表名: {reader["TableName"]}");
                    Console.WriteLine($"索引名: {reader["IndexName"]}");
                    Console.WriteLine($"碎片率: {reader["avg_fragmentation_in_percent"]}%");
                    Console.WriteLine($"页数: {reader["page_count"]}");
                    Console.WriteLine("---");
                }
            }
        }
    }
}

public void ReorganizeOrRebuildIndex(string tableName, string indexName, double fragmentation)
{
    string connectionString = "your_connection_string_here";
    string commandText;

    if (fragmentation > 30)
    {
        // 碎片严重，重建索引
        commandText = $"ALTER INDEX [{indexName}] ON [{tableName}] REBUILD";
    }
    else if (fragmentation >= 10)
    {
        // 中等碎片，重新组织
        commandText = $"ALTER INDEX [{indexName}] ON [{tableName}] REORGANIZE";
    }
    else
    {
        Console.WriteLine("碎片率低，无需处理。");
        return;
    }

    using (SqlConnection conn = new SqlConnection(connectionString))
    {
        conn.Open();
        using (SqlCommand cmd = new SqlCommand(commandText, conn))
        {
            try
            {
                cmd.CommandTimeout = 300; // 设置超时时间，防止长时间阻塞
                cmd.ExecuteNonQuery();
                Console.WriteLine($"{(fragmentation > 30 ? "重建" : "重组")}索引 {indexName} 完成。");
            }
            catch (Exception ex)
            {
                Console.WriteLine($"执行失败: {ex.Message}");
            }
        }
    }
}

// 示例调用
CheckIndexFragmentation();

// 或对特定索引进行处理
ReorganizeOrRebuildIndex("dbo.YourTable", "IX_YourColumn", 25);