A few days ago Salvatore Sanfilippo wrote about his work on a new Redis diskstore – a reworking of the old VM layer based on a different set of assumptions and tradeoffs. I was very interested in the new approach because it is very similar to the RethinkDB caching architecture in principle. When we designed our caching layer we had a number of constraints we needed to satisfy:

• Performance – the system needed to work at memory speeds when the data fits into RAM, as well as when the data far exceeds the amount of available RAM, but the active working dataset mostly fits into RAM. Once the active dataset no longer fits into RAM, the system still needs to work at the speed of the underlying storage layer.
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On my computer, the callstack of a new process is around 10MB*. Modern operating system automatically reserve some amount of virtual memory and install protections on the page below the stack to create a segmentation fault on stack overflow. This ensures that a stack overflow won’t go corrupting random parts of memory.

We want to have a lot of coroutines, so they should have smaller stacks, maybe 16 or 64KB. This makes stack overflow an even greater possibility, but at the same time, coroutines implemented in user space don’t get this checking for free—we have to build it ourselves. In the process, we can even do better: we can give some information about the coroutine which crashed. Here’s the idea:

• Memory-protect the page on the bottom of the stack (remember, x86 callstacks grow down) to disallow reads and writes.
• Install a signal handler for SIGSEGV.
• In the handler, examine which address …

Previously, I wrote about using coroutines in RethinkDB. Coroutines are a nice alternative to callbacks because they are easier to program in, and they are a nice alternative to threads because of their greater performance. But how fast are they?

Just using an off-the-shelf library like libcoroutine isn’t as fast as you might think. The graph below shows the huge performance degradation of a naive implementation of coroutines (the short red bar) compared to the old callback-based code (the blue bar on the left). But with the right set of optimizations, we can recover a level of performance about equal to the non-coroutine version. With these optimizations, throughput is recorded as the pink bar on the right, which is within the margin of error of the original version.

The improvement comes from  two …

We’re proud to announce the next release of MySQL Workbench, version 5.2.31. This is a maintenance release focusing on general product improvement and usability.

We managed to close 97 bugs for this release.

MySQL Workbench:  Remote Administration on Windows – Support for Windows “Remote” Management within the New Server Instance Wizard and Manage Server Instance Form. This works for servers on the same domain (or trusted) – ie typical Windows LAN environments.  We expect Windows users to prefer this “native” way to do remote admin on Windows.  SSH remote admin has been available for some time on Windows, Mac OS, and Linux.

MySQL Workbench:  Utilities Plugin – Starts a shell that contains a set of python scripts that perform basic tasks such as copying, exporting, and importing databases, finding database objects or processes, cloning servers and cloning users.

MySQL Workbench: …

We’re proud to announce the next release of MySQL Workbench, version 5.2.30. This is a maintenance release focusing on general product improvement and usability. In addition to that, we have added a small set of Text-Formatting-Plugins to the SQL Editor to help format/structure your SQL Queries.

As always, we want to thank everyone for the great feedback we have received. This helps us to continuously improve the functionality and stability of MySQL Workbench – we appreciate all your ideas for improving MySQL Workbench.  Please keep sending us your ideas!

About the Query-Formatter

In the Edit->Format menu of Workbench’s SQL Editor you will see a set of functions that assist in reformatting your SQL Queries, for example “Beautify Query”, “UPCASE Keywords”, etc.

MySQL Workbench 5.2 GA

• Data Modeling
• Query (replaces the old MySQL Query Browser)
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Go to devart.uservoice.com and share your ideas about new features you want to see in dbForge Studio for MySQL. Here you can do the following:

• Vote for features that are already in our roadmap, and they will get higher priority in our plans
• Suggest your own features, and if they get enough votes, we will include them to the roadmap.

Your opinion helps us to make our MySQL GUI Client better and more useful for you.

We have already started implementing the following features:

Export data of the several tables at once

Data Export …

We’re proud to announce the next release of MySQL Workbench, version 5.2.29. This maintenance release focuses on general product improvement and usability.

As always, we want to thank everyone for the great feedback we have received. This helps us to continuously improve and extend the functionality and stability of MySQL Workbench – please keep up on approaching us with any ideas to develop our product even further.

New Workbench 5.2.29 Preference/Feature

Say you have been working on a model for hours in Workbench, and you haven’t saved in the last 90 minutes, suddenly the power goes out (or some other force majeure). Now with 5.2.29, if Workbench unexpectedly quits during modeling, the model you were working on will be restored to the last auto-saved version the next time you open that model.
As always, please remember to save and version your models regularly.
Also – you can change the value of …

We’re proud to announce the next release of MySQL Workbench, version 5.2.28. This maintenance release features improvements to the Workbench scripting Shell as well as various fixes.

Enhancements to the Workbench 5.2.28 Scripting Shell makes development and usage of Workbench Scripts and Plug-ins easier by

• Providing a new workbench shell scripting file browser
• Allowing users to more easily create/edit/save/execute Workbench python and lua scripts
• Including Handy Workbench “Scripting” snippets that can easily be executed or copied.
• Adding a new script results output panel

For more on Workbench Scripting and Plug-in development see

http://wb.mysql.com/?page_id=664

As always, we want to thank everyone for the great feedback we have received. This helps us to continuously improve and extend …

Devart made it to the final of 2010 DevProConnections Community Choice Awards. The awards recognize the best products and services in the industry by a community vote.

Devart has been nominated in 4 categories of 2010 DevProConnections Community Choice Awards!
Nominated products:

• Best Add-In Product – Entity Developer (page 1, category 1: Add-In)
• Best Component Set – dotConnect for Oracle (page1, category 7: Component Set)
• Best IDE Product – dbForge Studio for MySQL (page 2, category 14: IDE)
• Best Free Tool – CodeCompare (page2, category 26: Free Tool )

If some of your favorite products are in that list, please visit: …

We’re proud to announce the next release of MySQL Workbench, version 5.2.27. This is the second maintenance release for 5.2 GA (Generally Available). This maintenance release does not introduce any new features, but focuses on general product improvement and usability.  We hope you will make MySQL Workbench your preferred tool for Design, Development, and Administration of your MySQL database applications.

As always, we want to thank everyone for the great feedback we have received. This helps us to continuously improve and extend the functionality and stability of MySQL Workbench – please keep up on approaching us with any ideas to develop our product even further.

MySQL Workbench 5.2 GA

• Data Modeling
• Query (replaces the old MySQL Query Browser)
• Administration (replaces the old MySQL Administrator)

Please get your copy from our Download site. Sources and binary …