Archive for the ‘mysql’ Category

MySQL ALTER table Progress Bar?

Thursday, May 15th, 2008

Altering a big table sucks, and to make it worse you have no idea what's happening or how long it will take. I'd like a progress bar, or some status output, or something that gives me the feeling like my server didn't die.

MySQL and Materialized Views

Tuesday, May 13th, 2008

I was poking around the MySQL Worklog again over the weekend, and found a request for materialized views for MySQL. This feature has existed in Oracle for a while, in DB2 as a materialized query table, and appeared in MS SQL Server 2000 and 2005 as indexed views. What is ...

MySQL: Time Delayed Replication

Wednesday, May 7th, 2008

I was cruising the MySQL Forge Worklog when I came across the idea of Time Delayed Replication. I had never considered the benefits of deliberately keeping a slave server behind a master. Kristian Koehntopp gives a good example: Kristian Koehntopp writes: TDS: Time delayed SQL_THREAD (Have a replication slave that is ...

MySQL Load Balancer

Wednesday, April 23rd, 2008

I'm not sure how I didn't see this earlier, but it looks like MySQL 5.1 is coming with a load balancer for replicated servers. I'm absolutely pumped about this - we've got a few sites running with multiple db slaves and it's so annoying having to check if they're ...

Decimal vs Float in MySQL

Tuesday, April 1st, 2008

While I've known how floating points are stored, I didn't know if decimal was stored any differently, or if it was more or less accurate. According to a post on the MySQL list: Bruno Rodrigues Silva wrote: > Dear all. > > The MySQL Manual inform that Decimal Data Type is used > ...

External Libraries in XCode

Wednesday, February 6th, 2008

I need to compile something and use the MySQL C++ library. I have mysql and mysql++ already compiled, I won't go over how to do that now. I added the following code to the top of my source: #include <mysql++.h> I got an error /Users/jhaddad/dev/search_engine/main.cpp:4:21: error: mysql++.h: No such file or directory Not ...

Altering tables in MySQL Cluster 5.0.45

Tuesday, November 13th, 2007

I'm setting up my first mysql cluster, and just wanted some clarification on a few things. In the manual, it says: Online schema changes. It is not possible to make online schema changes such as those accomplished using ALTER TABLE or CREATE INDEX, as the NDB Cluster engine does not support ...

Replication Issues - Duplicate Key Errors (1062)

Wednesday, October 31st, 2007

We were using replication to deal with certain queries that were producing table scans. I realize this is not a great long term solution but we were migrating a web site that was set up this way, so it wasn't really a choice. We had a database that was a ...

Checking MySQL Query Cache

Thursday, October 11th, 2007

MySQL query cache can be useful, if it works. Here's how to check it's effectiveness. show status like 'qc%'; +-------------------------+----------+ | Variable_name | Value | +-------------------------+----------+ | Qcache_free_blocks | 6407 | | ...

Innodb performance on windows?

Monday, June 11th, 2007

Let me first state that I've only run MySQL on Linux and MacOS X, never Windows. This is the first I've heard of Innodb having massive performance issues. Check out Karl Seguin's blog post.