PostgreSQL analog of SQL Server index

Question

Trying to recreate my SQL Server database on PostgreSQL. Everything is ok except I can't find how to recreate this index:

USE [mytablename]  
GO  
CREATE NONCLUSTERED INDEX [myindex]  
ON [dbo].[mytablename] ([col1],[col2])  
INCLUDE ([col3],[col4])  
GO

Will be very grateful for help.

Alexey

Update:

http://img38.imageshack.us/img38/1071/89013974.png here is db structure star+eav
there is only one query

SELECT this_.id as id0_0_,   
this_.device_id as device2_0_0_,  
this_.time_id as time3_0_0_,  
this_.gps_detail_id as gps4_0_0_   
FROM [scoutserver_data].[dbo].[DataMessage]  this_   
WHERE this_.time_id = 65536 and this_.device_id = 32768

Maybe it is not optimal atm. And im working on it also. Maybe something like this

SELECT * FROM [scoutserver_data].[dbo].[TimeDimension]   
  INNER JOIN ([scoutserver_data].[dbo].[DeviceDimension]   
  INNER JOIN  [scoutserver_data].[dbo].[DataMessage]   
ON [DeviceDimension].[device_id] =[DataMessage].[device_id])  
ON [TimeDimension].[time_id] = [DataMessage].[time_id]  
WHERE DeviceDimension.serial_id='2' AND TimeDimension.Day=15 AND TimeDimension.Year=2009

Any hints welcome =)

Answer 1

CREATE INDEX myindex ON mytablename (co1l, col2, col3, col4)

PostgreSQL does not support clustered or covering indexes.

Update:

For this query, you'll need to create the suggested index indeed:

SELECT  this_.id as id0_0_,   
        this_.device_id as device2_0_0_,  
        this_.time_id as time3_0_0_,  
        this_.gps_detail_id as gps4_0_0_   
FROM    DataMessage this_   
WHERE   this_.time_id = 65536
        AND this_.device_id = 32768

CREATE INDEX ix_datamessage_time_device_id_detail ON datamessage (time_id, device_id, id, gps_detail_id)

However, your tables seem to be over-normalized to me.

You can keep year, month and day in a single INT field in your table. This will save you a join.

There might be the point of keeping DataMessage and GpsDetails in separate tables if either GpsDetails are rarely linked to the DataMessage (this is, gps_details_id is often set to NULL), or a GPS details record can be shared between multiple data messages.

It it's not, it will be better to move the GPS details into the data messages table.

Answer 2

http://img38.imageshack.us/img38/1071/89013974.png here is db structure star+eav
there is only one query

SELECT this_.id as id0_0_,   
this_.device_id as device2_0_0_,  
this_.time_id as time3_0_0_,  
this_.gps_detail_id as gps4_0_0_   
FROM [scoutserver_data].[dbo].[DataMessage]  this_   
WHERE this_.time_id = 65536 and this_.device_id = 32768

Maybe it is not optimal atm. And im working on it also. Maybe something like this

SELECT * FROM [scoutserver_data].[dbo].[TimeDimension]   
  INNER JOIN ([scoutserver_data].[dbo].[DeviceDimension]   
  INNER JOIN  [scoutserver_data].[dbo].[DataMessage]   
ON [DeviceDimension].[device_id] =[DataMessage].[device_id])  
ON [TimeDimension].[time_id] = [DataMessage].[time_id]  
WHERE DeviceDimension.serial_id='2' AND TimeDimension.Day=15 AND TimeDimension.Year=2009

Any hints welcome=)