Question

我有2个用于物联网项目的真正大的SQL服务器数据库表

First TABLE IS Message（行数7,423,889,085行）

app.UseWhen(context => !context.Request.Path.StartsWithSegments("/api"), branch =>
{
    branch.UseIdentity();
});

第二个表是MessageSensors，行数（26,359,568,037行），此表具有消息表中每个传感器的值

CREATE TABLE [aymax].[Message](
    [MessageId] [bigint] IDENTITY(1,1) NOT NULL,
    [ObjectId] [int] NOT NULL,
    [TimeStamp] [datetime] NOT NULL CONSTRAINT [DF__Message__TimeSta__3B75D760]  DEFAULT (getdate()),
    [GpsTime] [datetime] NOT NULL,
    [VisibleSatelites] [int] NOT NULL,
    [X] [float] NOT NULL,
    [Y] [float] NOT NULL,
 CONSTRAINT [Message_PK] PRIMARY KEY NONCLUSTERED 
(
    [MessageId] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]

GO

我的问题是在2个日期时间之间的时间间隔寻求真的很慢，如果我选择了消息传感器数据也会变得更慢，同时当我使用来自brentozar.com的sp_BlitzIndex检查它说我有

＆＃34; Indexaphobia：高价值缺失指数＆＃34;


[aymax]。[MessageSensors]（EQUALITY：[DataSourceId]，[Value]包括：[MessageId]）

[aymax]。[MessageSensors] EQUALITY：[Value]包括：[MessageId]，[DataSourceId]

我相信创建这个2索引会增加存储空间，也会花费太多时间来创建，我需要你对这两个关于索引的表的建议

我当前的索引

1 -

CREATE TABLE [aymax].[MessageSensors](
    [MessageId] [bigint] NOT NULL,
    [DataSourceId] [int] NOT NULL,
    [Value] [float] NOT NULL CONSTRAINT [DF__AnalogDat__Value__5812160E]  DEFAULT ((0)),
 CONSTRAINT [AnalogData_PK] PRIMARY KEY CLUSTERED 
(
    [MessageId] ASC,
    [DataSourceId] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]

GO

2 -

    CREATE NONCLUSTERED INDEX [IX_gpstime_objectid] ON [aymax].[Message]
(
    [GpsTime] ASC
)
INCLUDE (   [MessageId],
    [ObjectId]) WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON)
GO

第三 -

alter TABLE [aymax].[Message] ADD  CONSTRAINT [Message_PK] PRIMARY KEY NONCLUSTERED 
    (
        [MessageId] ASC
    )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, IGNORE_DUP_KEY = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON)
    GO

4 -

ALTER TABLE [aymax].[MessageSensors] ADD  CONSTRAINT [AnalogData_PK] PRIMARY KEY CLUSTERED 
(
    [MessageId] ASC,
    [DataSourceId] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, IGNORE_DUP_KEY = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON)
GO

任何帮助请，我需要从消息和消息传感器快速检索

更新在进行一些调查时我发现选择浮动值会使结果放慢太多，从1秒到3分钟

CREATE NONCLUSTERED INDEX [MessageData_DataSourceId_IDX] ON [aymax].[MessageSensors]
(
    [DataSourceId] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON)
GO

Answer 1

可能的解决方案：

过滤索引（按日期过滤，不要索引旧数据） https://docs.microsoft.com/en-us/sql/relational-databases/indexes/create-filtered-indexes。
GpsTime上的聚簇索引，MessageId（特别是如果您没有关于其他索引的计划）。需要重建你的桌子。
分区（参见@ Siyaul的评论）

SQL Server从大表中选择慢

1 个答案: