Simple select by RID

[Greg T]

Hi
I am new to OrientDb and already impressed (missing only .NET
integration)
But I am having problem with something very simple: what is the syntax
for selecting by RID, eg:

SELECT * FROM ORole WHERE RID = #3:0

I've tried every possible combination but have no idea how to pass the
RID (single and multiple)

Thanks

[Alessandro Nadalin]

On Mon, Feb 13, 2012 at 3:14 PM, Greg T <gtrz...@gmail.com> wrote:
> Hi
> I am new to OrientDb and already impressed (missing only .NET
> integration)
> But I am having problem with something very simple: what is the syntax
> for selecting by RID, eg:
>
> SELECT * FROM ORole WHERE RID = #3:0

SELECT * FROM #3:0

or

SELECT * FROM ORole WHERE @rid = #3:0

>
> I've tried every possible combination but have no idea how to pass the
> RID (single and multiple)
>
> Thanks

--
Nadalin Alessandro
www.odino.org
www.twitter.com/_odino_

[Greg T]

Thanks Alessandro, that's exactly what I needed!

The multiple (in list) also works nicely now with "@rid":
SELECT * FROM ORole WHERE @rid in [#3:0,#3:1]


On Feb 13, 2:18 pm, Alessandro Nadalin <alessandro.nada...@gmail.com>
wrote:

[Luca Garulli]

Alessandro is right,

just note that this

SELECT FROM  [#3:0,#3:1]

it's much faster than

SELECT * FROM ORole WHERE @rid in [#3:0,#3:1] 

Lvc@

[Elad]

Hi Luca,

Can you please explain why the first one is much faster?

Intuitive it looks the same, and it might be a trap for developers ( like us ;) )

[scott molinari]

I'd say it is because the rids are physical locations, so it is easy for ODB to just go directly to the records and get them with the FROM [#rid, #rid] clause. Whereas, the WHERE clause is a filter, which means there needs to be a separation of the records from a complete list (scan) of all the records. One would think the system would be smart enough to reduce the WHERE/IN when using @rid to the simpler SELECT/FROM form, but I am sure there are technical reasons why this isn't directly possible.  

Scott 

[Luca Garulli]

Hi guys,

OrientDB SQL engine should be smart enough on this simple query to rewrite it with the optimized version, but if you start adding conditions, parenthesis, etc. it couldn't be that smart.

Best Regards,

Luca Garulli

Founder & CEO

OrientDB

On 9 February 2016 at 15:06, scott molinari <scottam...@googlemail.com> wrote:

I'd say it is because the rids are physical locations, so it is easy for ODB to just go directly to the records and get them with the FROM clause. Whereas, the WHERE clause is a filter, which means there needs to be a separation of the records from a complete list (scan) of all the records. One would think the system would be smart enough to reduce the WHERE/IN when using @rid to the simple SELECT/FROM form, but I am sure there are technical reasons why this isn't directly possible.  

Scott 

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[scott molinari]

Thanks Luca. 

Was my assumption about the difference between the two queries actually correct? 

And please don't take my comment as a slant or anything close. I love ODB and fight for it, where and when I can. You know that. :-)

Scott