Planet MySQL Planet MySQL: Meta Deutsch Español Français Italiano 日本語 Русский Português 中文
10 Newer Entries Showing entries 61 to 70 of 1030 10 Older Entries

Displaying posts with tag: sql (reset)

Introducing MySQL Connector/Arduino 1.0.0 beta
Employee +4 Vote Up -0Vote Down

There is a new release of the Connector/Arduino on Launchpad! See The new version supports a number of refinements and a few new features. These include:

  • Improved support for processing result sets
  • Conditional compilation to omit result set handling features to save program space
  • Support for the Arduino WiFi shield
  • New version() method to check version of the connector
  • Simplified download (no more patching SHA1!)

So What is It?
If you have never heard of Connector/Arduino, it is simply a library designed …

  [Read more...]
Announcing: New Forum for Connector/Arduino!
Employee +0 Vote Up -0Vote Down

Due to the growing popularity of Connector/Arduino, the moderator of MySQL Forums has created a forum for us to meet up and discuss the connector. Yippie!

While the forum has been started very recently, I expect it will grow quickly as people discover the connector for the first time and experienced users find new and interesting ways to use it. I hope to moderate the new forum periodically to answer questions and respond to posts. See you there!

Note: you need an account to write to the forum. Click on …

  [Read more...]
Building Queries Systematically
Employee +0 Vote Up -0Vote Down

The SQL language is a bit like a toolkit for data. It consists of lots of little fiddly bits of syntax that, taken together, allow you to build complex edifices and return powerful results. For the uninitiated, the many tools can be quite confusing, and it's sometimes difficult to decide how to go about the process of building non-trivial queries, that is, queries that are more than a simple SELECT a, b FROM c;

A System for Building Queries

When you're building queries, you could use a system like the following: 

  1. Decide which fields contain the values you want to use in our output, and how you wish to alias those fields
  [Read more...]
MySQL isn’t limited to nested-loop joins
+2 Vote Up -0Vote Down

I have followed the “Use the Index, Luke!” blog for a while. Today Marcus wrote that (I’ll paraphrase) MongoDB disgraces NoSQL the same way that MySQL disgraces SQL. I agree with a lot of this, actually, although I’m not sure I’d put it so strongly. People often like products for good reasons, and to think that legions of developers are stupid or ill-educated is suspect, in my opinion.

But that wasn’t what I meant to write about. I …

  [Read more...]
It happened again
+1 Vote Up -1Vote Down

Oracle released a bunch of MySQL stuff they’ve been working on since the last huge release, and my blog reader filled up with a few dozen posts I’m gonna have to read through …

  [Read more...]
How to find unused MariaDB/MySQL accounts
+1 Vote Up -0Vote Down

In MariaDB and Oracle MySQL, an account is a user_name@host combination, where host can be an ip address (v4 or v6) or a hostname. Also, the host part can be specified as a LIKE pattern (such as '161.58.%'). The account used by the connection determines the privileges for that connection. When a connection matches more than one account, only one is used, and privileges assigned to other accounts will be ignored.

It can happen that you think that a certain client uses an account, but it uses a different account. For this reason, in this post I’ll show the queries to get all defined accounts, plus the accounts that were …

  [Read more...]
Sending the query to the data
+0 Vote Up -0Vote Down

It’s common wisdom that large-scale database systems require distributing the data across machines. But what seems to be missing in a lot of discussions is distributing the query processing too. By this I mean the actual computation that’s performed on the data.

I just had a conversation with Peter Zaitsev yesterday that helped make concrete some thoughts I’ve been having about Cassandra for a while. Because Cassandra doesn’t allow you to really do any computation in the data (aggregating, evaluating expressions, and so on), if you’re going to use it for truly Big …

  [Read more...]
Features I’d like in MySQL: windowing functions
+3 Vote Up -0Vote Down

Continuing with my wishlist, I’ll add windowing functions. They’re enormously powerful. They allow you to extend relational logic beyond the strict boundaries of tuples. In MySQL at present, one must use ugly hacks to preserve state from one row to the next, such as user variables — which are not guaranteed to work if the optimizer changes the query plan.

And yeah, PostgreSQL and SQL Server have windowing functions too, and once you’ve used them it’s a little hard to go back. This is in fact one of the main things I hear from people who …

  [Read more...]
Features I’d like to see in MySQL: CTEs
+1 Vote Up -0Vote Down

The pace of MySQL engineering has been pretty brisk for the last few years. I think that most of the credit is due to Oracle, but one should not ignore Percona, Monty Program, Facebook, Google, Twitter, and others. Not only are these organizations (and the individuals I haven’t mentioned) innovating a lot, they’re providing pressure on Oracle to keep up the improvements, too.

But if you look back over the last few years, MySQL is still functionally a lot like it used to be. OK, we’ve got row-based binary logging — but we had binary logging and …

  [Read more...]
Can TokuDB replace partitioning?
+1 Vote Up -0Vote Down

I’ve been considering using TokuDB for a large dataset, primarily because of its high compression. The data is append-only, never updated, rarely read, and purged after a configurable time.

I use partitions to drop old data a day at a time. It’s much more efficient than deleting rows, and it lets me avoid indexing the data on the time dimension. Partitioning serves as a crude form of indexing, as well as helping purge old data.

I wondered if TokuDB supports partitioning. Then I remembered some older posts from the Tokutek blog about partitioning. The …

  [Read more...]
10 Newer Entries Showing entries 61 to 70 of 1030 10 Older Entries

Planet MySQL © 1995, 2015, Oracle Corporation and/or its affiliates   Legal Policies | Your Privacy Rights | Terms of Use

Content reproduced on this site is the property of the respective copyright holders. It is not reviewed in advance by Oracle and does not necessarily represent the opinion of Oracle or any other party.