Telling what caches are, what a Result Cache is, how it is made in Oracle and in other databases is not very interesting and rather patterned. But everything gets completely different colors when it comes to specific examples.
Alexander Tokarev
( Shtock ) Built his report on Highload ++ 2017 on the basis of cases. And it was based on the cases, he told me when the home-made cache can be handy, what the pain of the server-side Result Cache is and how to replace it with the client, and in general brought up a number of useful tips for setting up Result Cache in Oracle.
 
 

 
 
The USRLE is a state register of legal entities in which 10 million Russian companies are kept. Manages the FTS directory.
 
 
From the USRLE we take the data of organizations for " Tips "," Single Customer "And" Factor ". In the article we will tell you how we lived before the directory, how we get access to it and how we work with it.
 
multistat.ru - this is a legal reseller who sold the data of the Federal Tax Service. The problem is that Multistat gave its base with a high price without updates.
 
 
Therefore, we maintained the relevance ...

 
 
Once we decided to see what seasonal interests there are among users of 2GIS in different cities. Splashes of interest in flowers, New Year's gifts and tires - are quite expected. We decided not to limit ourselves to them and go further, having checked all areas of activity in all 113 cities of presence.
 
 
In this article I will tell you how we searched for seasonality and what features of user behavior they found.
 
 
criterion of inversions .
 
 
If the hypothesis is not rejected, then it is ...

 
Abstract
 
Real-time data processing exactly once (
exactly-once
) - the task is extremely non-trivial and requires a serious and thoughtful approach throughout the entire calculation chain. Some even believe that such a problem is impossible. . In reality, one wants to have an approach that ensures fault-tolerant processing in general without any delays and the use of various data stores, which puts forward even more stringent requirements for the system:
concurrent exactly-once
and the heterogeneity of the persistent layer. To date, this requirement does not support any of the existing systems.
 
The p...

Fuzzy logic for control

 
The text is based on the materials of the book Gostev VV. "Fuzzy regulators in systems of automatic modeling". Like all serious publications on the topic, this book is overloaded with mathematical calculations and is hard for an unprepared reader. Meanwhile, the very principles of creating and using fuzzy logic are quite simple and obvious. This text is an attempt to translate an example from a book from a mathematical language into an engineering one.
 
The possible sequence of controller design based on fuzzy logic is shown, by sequential complication of logical ...[/h]

 
 
Simple code for debugging is code that does not fool you. It is more difficult to debug code with hidden behavior, with poor error handling, with uncertainties, insufficiently or excessively structured, or in the process of changing. In fairly large projects, you eventually encounter a code that you can not understand.
 
 
If the project is relatively old, then you can find code that you forgot about, and if it were not for the commits, you would have sworn that you did not write these lines. As the project grows, it becomes more difficult to remember what the different pieces of code are doing. And ...

 
 
The SOLID principles are a programming standard that all developers need to understand well in order to avoid creating a bad architecture. This standard is widely used in OOP. If you apply it correctly, it makes the code more extensible, logical, and readable. When a developer creates an application based on poor architecture, the code turns out to be inflexible, even small changes in it can lead to bugs. Therefore, you must follow the principles of SOLID.
 
 
It takes some time to master them, but if you write the code in accordance with these principles, its quality will improve, and you will master ...

By implementing modern information systems, large companies expect to make decisions faster, discover hidden reserves and opportunities for the business, analyze the accumulated experience and build forecasts based on the identified regularities. However, the real return on information systems is often much lower, and implementation time and costs are higher than expected. The reasons can be a great many, including those related to ineffective management, the human factor, the outdated infrastructure.
 
 
Essential shortcomings are also in the information systems themselves. In this article, I ...

In the first part of Article we started talking about a new class of high-level domain models called conceptual. Unlike other similar models in conceptual models, the links between concepts are concepts themselves, and the model is built on the basis of identifying and describing the abstractions that served as the formation (definition) of the concepts of the subject domain. This allows end users to build and update domain models through simple and natural operations of creating, modifying and removing concepts and their entities.
 
 
Here, in the second part, let's talk about how a fully ...