Solr Pager 0.2.0 released

I’ve just published solr_pager a search component for Solr that should make paging easier. It’s main use should be by XSLT transformation (using XSLT writer), so one should not bother anymore with slow recursive XSLT hacks and only apply fast templates on paging list in search result. Initial version 0.2.0 can be found on http://devel.dob.sk/solr_pager. […]

XSLT – copy node with attributes without childs

Simple solution for not-so-trivial problem of copying xml node with all its attributes, but without child nodes. Without the last condition, solution is easy, one would use <xsl:copy-of>, but with it things are a bit harder, you should do smt. like: <xsl:copy select=”.”> <!– this copies element name –> <xsl:copy-of select=”@*”/> <!– this copies all […]

StartCom StartSSL certificate + nginx

Quick guide to use free and widelly accepted (week ago Microsoft added StartSSL certificates to known authorities !) SSL certificate on nginx webserver. create certificate on startssl.com download certificate (ssl.pem) and generated key (remove password from key using: openssl rsa -in ssl.key-pass -out ssl.key) download helper certificates (from http://www.startssl.com/certs/ (according to your class level, usually […]

dmlquery initial release

Just released initial release of dmlquery tool, for doing DML queries on SQL database (or anything perl DBI abstraction layer can handle) via formated XML files. Very useful for XML pipelining. With this and XML/XSLT transformations you can do very powerful thinks, like whole ETL tools for extracting data from one source (database, web…), transform […]

Solving MAX(COUNT()) problem 2 – optimizations

In previous post I’ve tried to present my solution for solving max(count()) problem.  The solution was slightly suboptimal and I’ve needed to speed it up a bit, because I’m using it now in some statistical calculations and every millisecond is important. This is original solution. CREATE VIEW data_view_source AS SELECT DISTINCT ON (dp_id) dp_id, ds_id […]

SQL timeline and statistical computations

This is simple way how-to generate time table (list of consequencing timestamps, or timeline) in PostgreSQL. Nothing spectacular, but might help you ,when trying to do some time based statistical selects (can feel like OLAP :-)). Code: CREATE OR REPLACE FUNCTION gen_time_list( tim IN TIMESTAMP, tim_stop IN TIMESTAMP, step IN INT) RETURNS TABLE(ts1 TIMESTAMP, ts2 […]

Solving MAX(COUNT()) problem

I’ve been solving problem of doing grouped MAX(COUNT()) in PostgreSQL, and because I’ve not found anything really usable out there (doing correlated sub-queries is definitely not good idea for thousands of records) I’ve had to find my own solution. Situation plan My configuration is a bit complicated to explain this, so i’ll try do it […]

LDAP + SASL authentification

I’ve found again, that simple things don’t get so simple in OpenSource world, and you have to do it yourself when you want something. That’s the difference, in the world of commercial software you have to, either pay big money or you never get feature you need (and mostly both ;-)) I’ve  slightly unusual and […]