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Displaying posts with tag: coding (reset)
Building BLOBs in MariaDB ColumnStore

My team and I are working on finalizing the feature set for MariaDB ColumnStore 1.1 right now and I wanted to take a bit of time to talk about one of the features I created for ColumnStore 1.1: BLOB/TEXT support.

For those who don’t know, MariaDB ColumnStore is a fork of InfiniDB which has been brought up to date by making it work with MariaDB 10.1 instead of MySQL 5.1 and has many new feature and bug fixes.

ColumnStore’s storage works by having columns of a fixed size of 1, 2, 4 or 8 bytes. These are then stored in 8KB blocks (everything in ColumnStore is accessed using logical block IDs) inside extents of ~8M rows. This is fine until you want to store some data that is longer than 8 bytes such as CHAR/VARCHAR.

To solve this for columns greater than VARCHAR(7) and CHAR(8) …

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The way I like to compile my Go programs – Makefile

I was on the quest of searching the Holy Grail of Go programming, and I found something, which I doubt that it is, but close enough – for the first sight.

I have several problems with GO, first, that I write my code on an OSX box, and I’ll run the programs on Linux hosts, so I have to solve the cross compilation; my second problem with Go, that I don’t really like the “There is a GO project folder, and all the GO projects are relying on” approach. It makes using GitHub painful.

The first problem of mine is easily achievable since GO 1.5: we only need a GOOS environment variable and we can compile to different OS-es (see more at Dave Cheney: http://dave.cheney.net/2015/08/22/cross-compilation-with-go-1-5) easily.

The second problem is easily solvable too, just we have to start using the GOPATH variable for every GO project we have.

I don’t really want to use any external dependencies, so I decided to …

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Universal Code Completion using ANTLR

While reworking our initial code completion implementation in MySQL Workbench I developed an approach that can potentially be applied for many different situations/languages where you need code completion. The current implementation is made for the needs of MySQL Workbench, but with some small refactorings you can move out the MySQL specific parts and have a clean core implementation that you can easily customize to your needs.

Since this implementation is not only bound to MySQL Workbench I posted the full description on my private blog.

My first impressions about Go language

I am fascinated. Maybe that should be enough, but I guess I have to write a bit more here because we are not on twitter.

I spent a few days to get know Go language, and now I am more than satisfied. I mean, all the project ideas which are floating in my head should be written in Go.

First of all, I have rewritten Mambo-collector to go (https://github.com/banyek/mambo) because I have faced some serious errors when I used it on CentOS 7 – I blame systemd -: If the process was running as root then after a few days of data collecting, killing that process was lead to restart the entire system, which is not a bug, it is a catastrophe. I tried to debug it several ways, but I am not sure where the problem is, it could be at the ‘loghandler’ redirection or any other place in python-daemon, or it is simply there is a buffer inside which overflows – I don’t really care, because mambo was just a proof of concept – what I used in …

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Parsing in MySQL Workbench: the ANTLR age

Some years ago I posted an article about the code size in the MySQL Workbench project and talked a bit about the different subprojects and modules. At that time the project consisted of ~400K LOC (including third-party code) and already then the parser was the second biggest part with nearly a forth of the size of the entire project. This parser project back then used the yacc grammar from the MySQL server codebase and was our base for all parsing tasks in the product. Well, things have changed a lot since these days and this blog post discusses the current parsing infrastructure in MySQL Workbench.

We started looking into a more flexible way of creating our parser infrastructure. Especially the generation of lexer and parser from the grammar was a long …

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For the brave: compiling Workbench 6.3 using Visual Studio 2013 on Windows

Compiling MySQL Workbench yourself is quite a common task for Linux users, even though the application is available precompiled for certain platforms ready from our download page and available in our yum and apt repositories. In this blog post we show you how to compile it on Windows.

Introduction

Doing a build on Windows is a totally different matter and most users never need to do that. It’s mostly intersting for those wanting own functionality or just being curious. But you should be an experienced Visual Studio user. It’s a complicated task and not a good start for a beginner. The key problem when building on Windows is that we cannot ship any 3rd party library we used. Instead you have to collect them all yourself. In order to ease that task we created the list below. Each library comes with a version number which usually specifies the minimum version to be used. Most of the time it’s not mandatory to use the exact …

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MySQL Workbench 6.0: Help is on the way…

Do you know this scenario: you are writing down  a stored procedure but you can’t for the life of you remember the exact syntax of that CASE statement? Has it to end with CASE or not? Can I use more than one WHEN part and how should that be written? Usually you end up opening a web page and read through the excellent MySQL online docs. However, this might cost too much time if you quickly need different statements and other detail info. Here’s where MySQL Workbench’s context help jumps in.

The server can help

It’s probably only known to the die-hard terminal operators who write most of their SQL queries in a MySQL console window: the MySQL server already has a stripped down set of help topics produced by the Docs team. That means you can always get at least the syntax but often far more information for a particular syntax element when you work with a server. When you …

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Building MySQL Database Applications with Go

Last night at the Golang-DC meetup I spoke about building (MySQL) database applications with Go. The meetup was well attended and people were very enthusiastic about Go. I spent a few minutes talking about Go in general, how VividCortex uses Go (we’ve built our agents, API servers, and all backend processes with Go), why we like it, some of the nice things it enables like making it easy to build very resilient programs, and then I gave the presentation, which I’ve embedded below.

Afterwards the discussion ranged to a lot of related topics. This was the best part of the evening for me. There were really great questions on a variety of topics, and insightful answers from everyone.

MySQL Workbench: Script for adding columns to all tables in a model

Here’s a quick Python script for adding columns for all tables in your EER model. This will create a create_time and update_time columns in all tables, but you can modify it to your needs. To execute:

  1. go to Scripting -> Scripting Shell…
  2. click the New Script toolbar icon at the top left corner
  3. select Python Script and specify some name for the script file
  4. click Create
  5. copy/paste the script there
  6. click the Execute toolbar button

Make sure to backup your model before running this!

The code

# get a reference to the schema in the model. This will get the 1st schema in it.
schema = grt.root.wb.doc.physicalModels[0].catalog.schemata[0]
# iterate through all tables
for table in schema.tables:
    # create a new column object and set its name
    column = grt.classes.db_mysql_Column()
    column.name = "create_time"
    # add it to the table …
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mysqlnd_qc and Symfony2

Previously I was writing about combining Symfony2 and mysqlnd to get more statistics on what is going on below the surface in the database communication when using a Symfony2 application via the Symfony2 profiler. Now that's not all that can be done and I gave some ideas for extending this. One idea was adding mysqlnd_qc support. mysqlnd_qc is the client side query cache plugin for mysqlnd. This provides a client-side cache for query results transparently without changing the application.

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