MySQL has a lot of string data types - CHAR, VARCHAR, BLOB, TEXT, ENUM and bunch of variants such as VARBINARY but I think it is not enough

I would also like to see type HEXCHAR which would be able to store hex strings, such as those returned as MD5() and SHA1() efficiently. With little modification it could work for UUID() as well (it adds some dashes). Currently it is quite inconvenient to deal with strings like that in MySQL. Either you store them as strings and waste space or you spend them as binary and deal with inconvenience of having not readable strings in the table OR adding UNHEX() everywhere - which also adds overhead.

Another one I would like to see is zBLOB or zTEXT (or call them BLOB COMPRESSED/ TEXT COMPRESSED) which would transparently compress the blobs when they are inserted and retrieved from the database - this would allow to avoid having COMPRESS()/UNCOMPRESS() everywhere which clobbers things or compressing/uncompressing on the client.

It would be best if last one is optimized so if BLOB is not used in any WHERE clause (HAVING, GROUP BY etc) you could actually transparently decompress it on the client and compress bad. Though this is likely to require more significant changes in MySQL so I would not expect to happen quickly. The basic support should not be that hard though.

---

Entry posted by peter | 2 comments

Add to: | | | |

The COLLABORATE 08 conference went very well this year with excellent attendance and, as usual, high quality and informative presentations.  The aspect I especially like about COLLABORATE as compared to other conferences is that it is user-driven and almost all the 500+ technical sessions were devoid of any marketing speak or selling of products.

I presented 3 sessions between IOUG and OAUG, which were all well attended with over 150 people per session.  I guess security is really starting to become ingrained at many organizations.  I was somewhat surprised at the number of organizations relatively current with CPU patches based on the informal and highly unscientific "show of hands" surveys.

The PowerPoint presentations from my 3 sessions can be downloaded here -

Oracle Applications Users Group (OAUG)

Oracle E-Business Suite Critical Patch Updates: Insight and Understanding

Independent Oracle Users Group (IOUG)

Oracle Database Critical Patch Updates: Unwrapped

Real-life Database Security Mistakes

 

hdlm 5.9是hds多路径软件最新版本的，它与以前版本有不小的改进，比如以前一个ldev，如果有4个通道，那么在os上面可以看到4个hdisk，然后这个hdisk再组成一个dlmfdrv，在5.9中只有一个hdisk，没有dlmfdrv等等。在hacmp中配置的话，也有一些改动1.Method to identify ghost disks用下面这个角本，还是没变。/usr/DynamicLinkManager/cluster/dlm_hacmp_gdisk_check2.Method to identify ghost disks要采用"SCSI3"，以前的角本已经没了。3.disk type设置为：disk/fcp/Hitachi

Welcome to the 93^th edition of Log Buffer, the weekly review of database blogs.

Conference season is upon us, so it’s been a busy week. There was the MySQL Conference & Expo, so let’s look at that.

Arjen Lentz posts about Sunday’s community dinner, including the arrival of an unexpected guest. Two photos: one of Pythian’s Paul Vallée getting some Sun; the second from the pre-conference dinner.

Zack Urlocker has a couple pieces with both photos and links to video of the keynote addresses from Marten Mickos, Jonathan Schwartz, and Rich Green. From Wednesday, and from Thursday.

Congratulations are due to Baron Schwartz, Diego Medina, and Sheeri Cabral. Baron reports from the conference that the three of them were awarded the 2008 MySQL Community Awards, and his piece makes for a very apt acceptance speech. Here’s Kaj Arnö’s more official post on the Community Awards.

Baron also has good summaries of the conference course: day one, and day two.

Elsewhere on the MySQL scene, much ado about the immediate roadmap for the DBMS, as introduced at the conference. Jeremy Cole got things going, writing, MySQL to launch new features only in MySQL Enterprise: “MySQL will start offering some features . . . only in MySQL Enterprise. This represents a substantive change to their development model — previously they have been developing features in both MySQL Community and MySQL Enterprise. However, with a shift to offering some features only in MySQL Enterprise, this means a shift to development of those features occurring . . . only in MySQL Enterprise.” This post got a lot of comments, including from MySQL boss Marten Mickos.

(more…)

Shadowman on your shoulder?
Fedora on your forearm?
Tux on your tush?

We’re looking for people with Red Hat, Fedora, Creative Commons, and other awesome open source and related tattoos to feature in the magazine.

Even better, have you been thinking about getting some new geek ink but haven’t yet? Have a friend videotape it and send us the footage.

If you’re interested in showing off your ink, drop us a line.

Thanks!

Author:NinGoo posted on NinGoo.net

毫无疑问，开源运动最初更多的是一种精神运动，虽然最终不可避免的被商业化。Sun显然没有真正的理解开源，甚至没能合格的利用开源。虽然Sun一直在抱怨说向开源社区贡献了最多的源代码却没有得到应用的尊重，虽然已经将压箱底的Java和Solaris都整成了OpenJava和OpenSolaris，但看起来这更多的是被逼无奈，而不是真心的拥抱开源。

现在Sun说要对MySQL选择性开源，一些企业级新特性的源代码将不再开放，患得患失的小家子气一下表露无遗。保留的这些代码未必能吸引更多的客户，却让原本对于Sun收购MySQL持观望态度的开源人士找到了攻击和离开的借口，如此费力不讨好的事情，Sun居然能堂而皇之的在The 2008 MySQL Conference & Expo期间干出来，真是脑子进水了。

开源是一种精神，半推半就是不能赢得人心的。

Related Articles

• Sun收购MySQL?
• SlideShare：Web2.0在于分享
• Redhat上安装Perl DBD::mysql驱动
• 给MySQL DBA推荐一本书
• MySQL Proxy工作机制浅析

Add Comments(0)

Author:NinGoo posted on NinGoo.net

家里的台式机上装了个alexa工具条，今天偶然发现blog的排名出现了大幅度的上升，于是进去看了下，发现alexa的排名算法做了比较大的修改。原来alexa的排名的主要数据来源是alexa工具条，这个东西，除了一些个人站长或者专门帮别人刷排名的，估计安装的不多，所以得到的数据的准确度是值得怀疑的。想想以前国内多少网站靠着这个排名作为拉到风险投资的救命稻草，原来不过是建在沙滩上的城堡而已。每一次alexa排名算法的变化，都是有人欢喜有人叫，呵呵。

现在还拿alexa说事的应该不多了，web2.0们都喜欢说自己有多少注册用户有多少用户生成的内容了，没了关注度的alexa做出了最大的一个改变，不再过于依赖工具条的数据了。从一开始知道alexa，就对他们依赖工具条的数据来做排名就觉得很疑惑，他们居然说In recent months才收到用户的抱怨，借口而已吧，真正的原因，是一直无法获得足够的数据呢？还是一直写不出算法？

When Alexa began displaying rankings in 1998 it was with the goal of showing Alexa Toolbar users how popular any given site was within the Alexa community. We generated the rankings through an analysis of Internet usage by people who use the Alexa Toolbar. Since that time we’ve been delighted to see that the Alexa Rankings have become a yardstick by which website popularity is measured. We are grateful to the thousands of people who come to Alexa.com each day to check the Alexa Rankings.

In recent months we’ve heard from our Alexa users that understanding Internet usage beyond Alexa Toolbar users was increasingly of interest. Ask and you shall receive!

We listened to your suggestions, and we believe that our new rankings system is much closer to what you asked for. We now aggregate data from multiple sources to give you a better indication of website popularity among the entire population of Internet users.

Related Articles

• 升级到wordpress 2.5
• NinGoo@Net里程碑：日访问独立IP突破500
• 关于Dreamhost合租
• 恭喜淘宝DBA团队Blog开通
• BloggerMap发布同城地图Widget

Add Comments(0)

在测试环境中发现了这个错误，根据错误信息初步判断，和高级复制环境有关。在alert日志中，错误信息为：Errors in file /data/admin/testdata/udump/testdata_ora_29441.trc:ORA-26500: error on caching "NDMAIN"."CAT_AUTH_BAD_DRUG"检查trace文件中的详细信息：*** SESSION ID:(46.31281) 2008-04-04 13:31:03.942kniacfcb: ORA-26500 (line 3015) column "PROCLAMATION_NUMBER" doesn not exist*** 2008-04-04 13:31:03.979kniacfcb-1: ORA-26500 for NDMAIN.CAT_AUTH_BAD_DRUGkntklc: encountered error 26500 leading to ora-23474O...