Path: utzoo!attcan!uunet!lll-winken!lll-tis!helios.ee.lbl.gov!pasteur!ucbvax!hplabs!hpda!hpcuhb!hpsmtc1!donovan
From: donovan@hpsmtc1.HP.COM (Donovan Hsieh)
Newsgroups: comp.databases
Subject: Re: File data imported into SQL db's
Message-ID: <11410001@hpsmtc1.HP.COM>
Date: 17 Jun 88 01:12:08 GMT
References: <236@tijc02.UUCP>
Organization: Hewlett Packard, Cupertino
Lines: 28

In the article, David Marks <djm408@tijc02.UUCP> writes :

>I have heard that some SQL databases can import fields from a file
>into attributes of relations. I have also heard that this can be done from
>a file that originated from a device externally networked to the device on
>which the SQL database resides. Has anybody had any experience with this?
>How efficient/inefficient is this compared to a remote SQL query from a
>device networked to an SQL db?

I believe that many SQL based database provide such kind of import/export
capabilities between external files and their database relations. HPSQL, a
SQL based relational database from Hewlett-Packard provides LOAD & UNLOAD 
commands which will perform exactly what you are asking. As for the import/
export from different devices on the network (I assume that your "device
externally networked" refers to the remote mounte disks using NFS or RFA), I
don't see any difficulty on the UNIX implementation. As for the efficiency (
I bet you mean performance) issue, my experience is that it's acceptable on 
HPSQL as long as the network traffic is not too bad.

One of the concern I think you should pay attention to is the mapping of 
attributes from the imported file to the database relations. Sometimes it may
become very messy if the field length or data type specified by the import/
export does not map correctly. It may insert tuples which contains garbage
information.


Donovan Hsieh
Software Development Technology Lab
Hewlett-Packard, Cupertino California