TRISS

Active development year: 2012

Summary

In-memory search system for persistent data with (mostly) conjunctive queries

Motivation

We want to develop open source search system for RTB (real-time bidding) purposes. Here's a sample of requirements for / characteristics of RTB system (note, that this is quite different than features, that traditional DBMSes offer):

• rapid response time (in tens of milliseconds max)
• tables usually have many columns (50 and more)
• most queries are conjunctive, i.e. they are in form of 't1 AND t2 AND ... AND tn', where t1 to tn are positive or negated terms
• queries contains constraints for many columns (usually for most of them)
• whole data set is few GB at most (it fits into memory easily)
• data set is updated rarely (which means we can afford to drop and recreate whole table instead of directly implementing inserts / updates / deletes)
• in most cases we are interested only in few first results (LIMIT is used extensively)

Features

Datatypes

• numerical
• string
• list (of numerical or strings)

Queries

All queries are in form of: 't1 AND t2 AND ... AND tn LIMIT k', where ti is one of:

• equals
• not equals
• contains
• not contains
• less
• greater
• less or equal
• greater or equal

Build and installation

Prerequisites

• build tool - http://www.scons.org/
• boost - http://www.boost.org/

Build

Build project with scons make [--release]. --release flag is optional and will compile library with -O2 optimization flag (without this flag project is built with -g and -O0 flags). This will generate libtriss.so shared library in build directory.

Installation

Install project with scons install [--release] (requires super user privileges). Following files will be copied:

• shared library libtriss.so to /usr/lib/
• Triss header files to /usr/include/triss

Uninstallation

Just do scons install --clean as super user

Usage

There's a simple demo for TRISS in demo/ folder. Take a look at demo/demo.cpp to see how to interact with TRISS.

Running the demo

What you need to do:

• install TRISS (refer to section above)
• do make in demo/ catalog (which will compile demo.cpp file with -ltriss flag for the linker)
• run demo executable

Performance

Running benchmark

Build the benchmark with scons benchmark --release, the executable will be placed under build/. You can check available benchmark options by doing ./build/benchmark --help

Results

Benchmark ran on Lenovo x220 with parameters:

• -c 12 (number of columns)
• -d 5000000 (number of documents)
• -t 2 (number of querying threads)

Generated data set was about 1.2GB.

10,000 random queries took 1s 180 ms.

Maturity

This project was never used commercially (though it was evaluated for production by at least one company) and was not tested beyond the benchmarking and tests under triss/tests. We do not consider it stable by any means and we do not plan to develop it further in the near future (so fork and play with it!).

Development

Running unit tests

First assure you have google test framework installed: http://code.google.com/p/googletest/ Then build the tests with scons target_test, where target is one of:

• engine
• common
• utils

The executables will be placed under build/ directory and can be run as an usual programs.

Editing source

We've used mostly vim and eclipse (but we provide no eclipse project files here).

About project

Project was done as the Bachelor's degree project at Wrocław University, Poland.

Name

TRISS stands for "The Revolution In Search Systems". Also, Triss is the name of brown-haired sorceress from Sapkowski's novels (https://en.wikipedia.org/wiki/The_Witcher)

Authors

• Olchawa Piotr (http://github.com/2easy)
• Pastuszka Przemysław (http://github.com/rtshadow)
• Rychlik Michał