[Info-vax] Looking for some text search ideas

[Jan-Erik Soderholm]

David Froble wrote 2014-09-27 00:49:
> Hein RMS van den Heuvel wrote:
>> On Friday, September 26, 2014 1:27:04 PM UTC-4, David Froble wrote:
>>>> Does anyone know of a more effective method
>> than a sequential pass through the data of searching a list of data
>> looking for text matches?
>> Yes. Use 2 (or 10) passes each processing 1/2 (or 1/10) of the data.
>> :-).
>
> I don't see how this would help ??
>
>> For an RMS sequential file, take 1/2 EOF. Read 8 (or so) blocks, Start
>> looking for a word on a word boundary which is smaller than
>> LRL, and added to the curent offset points to a similar word. Use
>> that as the stopper for the first stream, and use is for a
>> $FIND-by-RFA to kick of the second stream.
>
> No file access.  Data will be loaded into memory once, and then searched
> upon request.
>
>> Was that SQl just as a matter of example, or did you indeed want to
>> use SQL syntax, and columns as such,
>
> That was just an example that I seemed to remember...

 > SELECT * from PRODUCT where DESCRIPTION %like% gasket

SELECT * from PRODUCT where DESCRIPTION like '%gasket%'.

But yes, I think all got the idea... :-)

We have a system with split data in Rdb and RMS. Depending
on what the acutal need is I use different methods.

SEA on the actual RMS fles directly (usualy myself).
For simple checks.

Read and scan the file using Python. Usualy when there is
a web interface since we use Python for our web apps but
also for some housekeeping needs, clearing out old data.

Load the RMS data into a Rdb table.
When there are needs of joins against other Rdb data.

I have also experimented with the "Rdb Transparent
Gateway for RMS", but never had enough time to set it
up. But then you can use straight SQL using a mix of
Rdb and RMS sources just as evenrything was in the
same Rdb database. Joins and all.

Having your data in RMS is a mess today and the
performance advantage is long gone.

Jan-Erik