[ZODB-Dev] Fast * wildcard search and word-part indexing + B-tree interval search.

Vladimir Voznesensky vovic at smtp.ru
Tue Sep 16 05:49:59 EDT 2003


One addition to estimation function.

> Estimation function for [A,B) interval and ab?cd template is the 
> following:
> 1. If first 5 letters of B<"abacd" or of A>"abzcd", all the keys in 
> the interval does not match ab?cd.
> 2. If first 5 letters of A=of B="ab<some letter>cd", all the keys of 
> the interval do match.
> 3. Otherwise, possibly some of the keys do match, some-do not, and we 
> must consider sub-division of the interval.

Shure, we can exclude intervals of the form:
"ab<X>cd"<A[0:5] and B[0:5]<"ab<X+1>cd" where <X> is some character and 
<X+1> -- it's successor.

So, estimation function for [A,B) interval and ab?cd template becomes 
the following:
1. If first 5 letters of B<"abacd" or of A>"abzcd", all the keys in the 
interval does not match ab?cd.
2. If first 5 letters of A=of B="ab<some letter>cd", all the keys of the 
interval do match.
3. If first 5 letters of A>"ab<X>cd" and of B<"ab<X+1>cd", all the keys 
in the inteval do not match.
4. Otherwise, possibly some of the keys do match, some-do not, and we 
must consider sub-division of the interval.

Dear Christian, who is the maintainer of btree code?
I'm interested in writing btree interval searching subroutine and 
estimation functions hook in C by myself.
I'm not interested in writing estimation functions specifically for 
character strings (I follow another aims), but it seems that many folks are.
I can advise and help to write string estimation functions (I've wrote 
them for Berkeley DB) and appropriate indices for Zope IndexedCatalog.
I have no large experience in Zope and (Python+C) development.
I'm trying to find co-llaboratives and possible consumers of my work.

Farewell.

VV




More information about the ZODB-Dev mailing list