... and one more thing to add to what Richard said about APPEND FROM:

When APPEND FROM was created, in dBase/CPM times (1979), SQL syntax did not exist, so did not get implemented in any language, at least until 1986, far later than dBase.

El jue., 12 abr. 2018 4:16, Richard Kaye rkaye@invaluable.com escribió:

APPEND FROM is xBase. As others mentioned, it wants the physical file and a cursor is a temp file buried in your temp directory using sys(2015) to create the file name. The SQL SELECT doesn't care about the location of the physical file since you already have it open.

--

rk

-----Original Message----- From: ProfoxTech profoxtech-bounces@leafe.com On Behalf Of Gene Wirchenko Sent: Wednesday, April 11, 2018 8:32 PM To: profoxtech@leafe.com Subject: RE: Appending from a Cursor

At 11:10 2018-04-11, "John Weller" john@johnweller.co.uk wrote:

...

You could try

APPEND FROM DBF(alimport)

   [whack object="hand" target="forehead"]  I have used it in the

past, just not very often. When I checked my code, I searched for "append from (" instead of just "append from". Sometimes, 90% of the battle is knowing what to look for.

  I ended up using

<vfp> insert into (this.thiscode+"_cwkt") select * from (alimport) </vfp>

  I am puzzled why (alimport) works for the SQL but not the

append from, but whatever.

[snip]

Sincerely,

Gene Wirchenko

[excessive quoting removed by server]

Ok, so let me ask the $64,000 question: Which method is faster or better: Append From DBF( or Insert Into as Gene used?

I have a similar project were I am issuing the same query to multiple SQL databases/servers and then using the Append From DBF( command to aggregate the results from each individual query into a large, single cursor to use for actual processing.

I'm traveling today or I'd test this myself, but I have limited access. Figured I'd see if anyone else had already determined the best choice before I go poking around on my own.

Paul

-----Original Message----- From: ProfoxTech [mailto:profoxtech-bounces@leafe.com] On Behalf Of Ted Roche Sent: Thursday, April 12, 2018 6:18 AM To: profoxtech@leafe.com Subject: Re: Appending from a Cursor

On Wed, Apr 11, 2018 at 8:31 PM, Gene Wirchenko genew@telus.net wrote:

 I am puzzled why (alimport) works for the SQL but not the append

from,

but whatever.

I agree with you that it is un-intuitive that aliases work *almost* everywhere. It's one of those hundreds of FoxPro's "always been that way" things.

As others have said, APPEND FROM is ancient nearly-original XBase. While it was updated occasionally for new file formats, the main purpose of the command is a low-level IMPORT (sibling command) from foreign formats and not as a cursor-manipulation command, so it's intended for reading files-on-disk and not cursors.

As Ted would say, it depends on your environment. I doubt you will see any significant performance difference with a 100 row table. Big tables? Rotational vs SSD?

--

rk

-----Original Message----- From: ProfoxTech profoxtech-bounces@leafe.com On Behalf Of Alan Bourke Sent: Thursday, April 12, 2018 9:30 AM To: profoxtech@leafe.com Subject: Re: Appending from a Cursor

On Thu, 12 Apr 2018, at 2:18 PM, Paul H. Tarver wrote:

Ok, so let me ask the $64,000 question: Which method is faster or better: Append From DBF( or Insert Into as Gene used?

I remember seeing on fox.wikis.com that Insert-SQL can be up to 100x faster than Append from. Not sure how true that is.

I was planning a similar test to get some sense of the quantifiable difference but you did a great job, Dave! The verdict is in and ‘Insert into’ wins hands down!

That’s what happens when you dangle Foxpro problems in this group. It’s like bait we can’t resist!

Thanks! Paul

Sent from my iPhone

On Apr 12, 2018, at 11:49 AM, Dave Crozier DaveC@Flexipol.co.uk wrote:

Paul, I have been interested in testing this out myself, so in the interests of all I just ran a test inserting a 2,000,000 record table into another table with an integer PK index and a 20 character index (ID field) and the SQL Insert runs 75% quicker but only 25% quicker if the "select(" (suggested by Alan) for the inserted records is either a physical table or a readwrite cursor.

I suppose this confirms that using cursors to pre-fetch your data into memory is significantly faster for insertions as the required records are either in memory completely or filtered by VFP. As we all know making a cursor readwrite effectively makes a cursor perform the same as a physical table as it causes VFP to create a physical "table" which would appear to significantly degrade performance - understandable.

Hope this makes sense... have to go, made myself late for dinner, so if not I'll explain better tomorrow!!

Dave Crozier Software Development Manager Flexipol Packaging Ltd.

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-----Original Message----- From: ProFox profox-bounces@leafe.com On Behalf Of Paul H. Tarver Sent: 12 April 2018 14:19 To: profox@leafe.com Subject: RE: Appending from a Cursor

Ok, so let me ask the $64,000 question: Which method is faster or better: Append From DBF( or Insert Into as Gene used?

I have a similar project were I am issuing the same query to multiple SQL databases/servers and then using the Append From DBF( command to aggregate the results from each individual query into a large, single cursor to use for actual processing.

I'm traveling today or I'd test this myself, but I have limited access. Figured I'd see if anyone else had already determined the best choice before I go poking around on my own.

Paul

-----Original Message----- From: ProfoxTech [mailto:profoxtech-bounces@leafe.com] On Behalf Of Ted Roche Sent: Thursday, April 12, 2018 6:18 AM To: profoxtech@leafe.com Subject: Re: Appending from a Cursor

...

On Wed, Apr 11, 2018 at 8:31 PM, Gene Wirchenko genew@telus.net wrote:

I am puzzled why (alimport) works for the SQL but not the append

from,

...

but whatever.

I agree with you that it is un-intuitive that aliases work *almost* everywhere. It's one of those hundreds of FoxPro's "always been that way" things.

As others have said, APPEND FROM is ancient nearly-original XBase. While it was updated occasionally for new file formats, the main purpose of the command is a low-level IMPORT (sibling command) from foreign formats and not as a cursor-manipulation command, so it's intended for reading files-on-disk and not cursors.

-- Ted Roche Ted Roche & Associates, LLC http://www.tedroche.com

[excessive quoting removed by server]