Full Text Index Search

[James Milne]

On 27 Oct, 2004, at 07:24, Ruslan Zasukhin wrote:

> Valentina cannot do this.
> Valentina do have special INDEX BY WORDS for String, VarChar and TEXT
> fields. Up to now most developers are quite satisfied wit this.

 From what I can understand from other developers using IndexByWords, it 
will
probably be sufficient for my current needs.

> 2) about speed of LIKE in in Valentina.
> Yes James, it is much faster than in mySQL or others. Because of 
> internal
> Valentina structure. Let me to remind:
>
> If you have in mySQL table with 30 VarChar fields, then one record can 
> be in
> average say 30 * (15-20) = 600 bytes or more. To scan such table for 
> LIKE
> DBMS need load into RAM all this.
>
> Valentina instead use for each column one file.
> So we need scan only 20 bytes * N of records.
> For this example Valentina is expected to be 30 times faster.

OK- This makes sense!

> 3) in Valentina 2.0 we will use SOMETIMES the index file to be even 
> more
> faster. Example. Assume you have table in million of records. Assume 
> that
> you have only 10,000 different words in column. So index will contains 
> only
> 10,000 columns. Then using INDEX SCAN instead of COLUMN SCAN we get 
> speed
> even 100 times faster.

If IndexByWords is enabled in Valentina 1.0, does this not generate an 
index
for the column?

If so, does this index get used when performing a LIKE search?

> 4) Next, in Valentina 2.0 (you can see this in beta) we have introduce 
> new
> special STRING SEACH functions in V4RB API. Similar as you have on OS 
> X or
> emails app...

Cool; that sounds like it will be a nice upgrade when it becomes 
available.

> 5) Next, in 2.0 we have implement that not only left() function use 
> index,
> But also right() and substr().

This is also very nice!

> So James, I think you can look on Valentina 2.0 beta.
> I believe you will be impressed :-)

Beta sounds great!

However, I need to ship a product within a couple of months.

Will Valentina 2.0 be available for me to integrate into a shipping 
application by January?

For the time being, I'm intending using Valentina 1 and the 
IndexByWords property, with
a LIKE search. That might be sufficient for the time-being.

Thanks for your feedback, Ruslan.

--
Kind Regards,
James Milne