Version 2.0: the splitting of the node table

[ UPGRADE WARNING for Unidatab 2.0: The new version brings structural changes, in consequence older databases have to be migrated to the new standard (see this link). Besides, some functions have been improved in syntax and output. Therefore old documentation will reveal inappropriate in some cases and will be corrected gradually in the near future. … Continue reading Version 2.0: the splitting of the node table


Search functions

Introduction In this post we'll explore ways of selecting records by comparison of properties. Designing even the simplest scientific examples implied too many decisions on the theoretical level for us to risk here. Instead, we're going to fancy we need holidays. Let's see how we can retrieve properties of some hotels we have in memory. … Continue reading Search functions

Back to subdatabases, with tools

Our last query ? select find_record(i) from unid_node where a = -145 limit 2 was fast enough in reaching records containing a certain type of property, provided we added a generic partial symbol (-145) targeting this type. Now we must notice that it's exactly what does a subdatabase. No need to describe our properties for … Continue reading Back to subdatabases, with tools

A golden ratio of data management

Until now we learned that Unidatab is a complicated engine that makes the act of looking for information slower and clumsier. Our last query for instance involved isolating a set of values sharing the same type from a much larger set (symbols). This kind of query is slow when the sets are numerous. No comparison with a classical db. … Continue reading A golden ratio of data management

How to retrieve information

Defining good and better ways of extracting information from an SQL base is a field of investigation in itself, however there are some peculiarities in the structure of Unidatab, that make it unexpected to people used to classical SQL databases. What kinds of output can we then expect from Unidatab? In this post we are … Continue reading How to retrieve information

Note on coercion

In the last post we saw several means of organizing data, namely templates, subsumption, and examplification. However, those means could be made more effective if there was more direction on how they operate. For instance, examplify() should be able to feed a record without having to repeat type names explicitly, but we didn’t choose the … Continue reading Note on coercion

How to use subdatabases

Subdatabases (subdbs in short) do not differ deeply from formats, but provide a type-record and thus allow subrecords to be created according to a defined structure. When subdbs are there, functions such as examplify(), subsume(), templatize() and get_subject() become available. ? select * from subdbs i sdb n a t u: -47 ~ #Data Structure … Continue reading How to use subdatabases