Dear ramo...:
On Monday, May 10, 2021 at 5:39:55 AM UTC-7,
ramo...@gmail.com wrote:
> piątek, 7 maja 2021 o 15:44:43 UTC+2 dlzc napisał(a):
> > On Thursday, May 6, 2021 at 1:54:12 PM UTC-7,
ramo...@gmail.com wrote:
> > ...
> > > Is there any way to count rows that meet a certain coniditon
> > > in specific column without moving dbserver pointer?
> > Can you create an index on that date field, set ".not. empty()"
> > as one of the conditions, and get a count of indexed items?
> > If it is a "permanent" index, then you should have less
> > performance penalty.
> >
> > I don't do VO, so I cannot help beyond that. Something like:
> >
https://harbour.github.io/doc/rddads.html#adskeycount
>
> thank You for suggestion but a) I can make index FOR
> (condition) but it does not tell how many elements have
> been indexed (at least I do not know how to get it)
That was my hope, that VO had tools similar to those for ADS (not a part of (x)Harbour... a sort of SQL alternative).
The type of index used, the number of keys is stored in the index file:
https://www.clicketyclick.dk/databases/xbase/format/cdx.html#CDX_STRUCT
... not saying you use CDX files.
> and b) I do not use Harbour ADS so do not have any
> advanced functions&methods.
I was not trying to convert you. Just trying to get you 'out of the corner'. I hope someone chimes in with a way to accomplish your need. I'll shut up now.
David A. Smith