|
O*******A
发帖数: 7 | 2 What's your feeling about DS's email?
DS's 的Email 是否存在 SS 所说的问题？
==== below is a health check report email sent by MJ ==========
From: MJ
Sent: Sunday, March 16, 2014 8:52 AM
Subject: DB HC on mydbname/myservername looks good
Team,
The Health Check report of the mydbname Databases look good.
INSTANCE STATUS:
================
INSTANCE_NAME HOST_NAME TIMESTAMP OPEN_
MODE STATUS LOGINS STARTUP_TIME
SHU
---------------... 阅读全帖 |
|
a******e
发帖数: 36306 | 3 ☆─────────────────────────────────────☆
OracleDBA (OracleDBA) 于 (Sun Mar 16 12:55:51 2014, 美东) 提到:
What's your feeling about DS's email?
DS's 的Email 是否存在 SS 所说的问题？
==== below is a health check report email sent by MJ ==========
From: MJ
Sent: Sunday, March 16, 2014 8:52 AM
Subject: DB HC on mydbname/myservername looks good
Team,
The Health Check report of the mydbname Databases look good.
INSTANCE STATUS:
================
INSTANCE_NAME HOST_NAME TIMESTAMP ... 阅读全帖 |
|
b******s
发帖数: 25 | 4 Please contact:
Alex Melaik
Technical Engineering Recruiter
CATAPULT STAFFING, INC.
1820 Preston Park Blvd, Suite 1600, Plano, TX 75093
Office: 972-299-8809
Fax : 469-298-3473
Cell : 972-802-9627
A*********[email protected]
See below information from recruiter Alex. He said there are two very good
positions (senior software engineer) in Sugarland, TX. They are full time
positions in a global company with a salary range from 105-120K. Sugarland
has excellent elementary/middle/high scho... 阅读全帖 |
|
G*******9
发帖数: 4371 | 5 【 以下文字转载自 WashingtonDC 讨论区 】
发信人: Great2009 (栀子园主，诚招助手), 信区: WashingtonDC
标 题: DC在招IT工 ActioNet Positions。。。
关键字: IT 招人 ActioNet Positions Openings
发信站: BBS 未名空间站 (Sun May 25 21:23:16 2014, 美东)
我在帮朋友的朋友发帖，你可以发包子给我表示感谢，但是请不要问我更具体的问题。
呵呵。。。
ActioNet supports the Centers for Medicare and Medicaid Services in key
areas of health IT solutions delivery. We are looking for Java Developer (
all levels) and System Analysts (all levels) with experience at CMS, Health
IT, or similar systems development en... 阅读全帖 |
|
G*******9
发帖数: 4371 | 6 我在帮朋友的朋友发帖，你可以发包子给我表示感谢，但是请不要问我更具体的问题。
呵呵。。。
ActioNet supports the Centers for Medicare and Medicaid Services in key
areas of health IT solutions delivery. We are looking for Java Developer (
all levels) and System Analysts (all levels) with experience at CMS, Health
IT, or similar systems development environments. Our team members work with
their federal counterparts and business owners to help CMS reach its mission
goals. Our offices are located in Woodlawn, Maryland.
The qualified team member... 阅读全帖 |
|
r**i
发帖数: 2328 | 7 再说一遍，你很多概念不清。你前面那些帖子把DB，sql，RDBMS都等同起来。DB不光是
RDBMS, document-oriented, federated，graph db都算，你要质疑可以发信问SIGMOD
。:D
SQL不过是个language standard，没人会说它是个DB, nosql里面照样可以实现SQL。
Hadoop当然不是一个DB，HBase才是。不过，你似乎认为作bigdata的公司非得是直接作
Hadoop的, not true。
DB architect不是DBA，我已经说了，需要heavy coding。
看似你也没有Internet startup经验，Internet startup有其特殊性，自开始处理的就
可以是PB级的。
startup做过，才是真正多面手，哪里都能上。那谁要说跳出db框架，容易的很，去
startup锻炼一下就成。
关于app server，我看你的回帖大部分在repeating，或者提新的概念。这种没啥好争
的，jboss, tomcat作过也就是用过, cluster，jpa，jms也就是配置一下，又不是开发
这些。都... 阅读全帖 |
|
a**********k
发帖数: 1953 | 8 这个我来说句公道话。前面大家讨论时都把DB，SQL，RDBMS混用，
你我也一样， 反正大家都明白就行， 不是写正式论文。 何况他
来浙版讨论，算是客人， 现在回过来这样说他就不厚道了。他虽然
不是DB专业， 但也算是CS出身，这些基本概念应该不至于不懂。
这里顺便向不是这行的老乡科普一下。 DB就是常说的Database，
中文叫数据库. 传统的数据库模型是E. F. Codd发明的Relational模型。
实现RDB(Relational DB)的软件管理系统，就是RDBMS， 比如ORACLE，
MYSQL， SQL SEVER， IBM DB2等。
RDB的查询语言基于Relational Algebra, 或Relationa Calculus，
相当于数学里的一阶逻辑。 SQL就是标准化的RDB的查询语言。
纯粹的SQL因为基于一阶逻辑， 所以不是图灵完备(Turing-complete)的。
但常用扩充的SQL是图灵完备的。
SIGMOD |
|
r**i
发帖数: 2328 | 9 再说一遍，你很多概念不清。你前面那些帖子把DB，sql，RDBMS都等同起来。DB不光是
RDBMS, document-oriented, federated，graph db都算，你要质疑可以发信问SIGMOD
。:D
SQL不过是个language standard，没人会说它是个DB, nosql里面照样可以实现SQL。
Hadoop当然不是一个DB，HBase才是。不过，你似乎认为作bigdata的公司非得是直接作
Hadoop的, not true。
DB architect不是DBA，我已经说了，需要heavy coding。
看似你也没有Internet startup经验，Internet startup有其特殊性，自开始处理的就
可以是PB级的。
startup做过，才是真正多面手，哪里都能上。那谁要说跳出db框架，容易的很，去
startup锻炼一下就成。
关于app server，我看你的回帖大部分在repeating，或者提新的概念。这种没啥好争
的，jboss, tomcat作过也就是用过, cluster，jpa，jms也就是配置一下，又不是开发
这些。都... 阅读全帖 |
|
a**********k
发帖数: 1953 | 10 这个我来说句公道话。前面大家讨论时都把DB，SQL，RDBMS混用，
你我也一样， 反正大家都明白就行， 不是写正式论文。 何况他
来浙版讨论，算是客人， 现在回过来这样说他就不厚道了。他虽然
不是DB专业， 但也算是CS出身，这些基本概念应该不至于不懂。
这里顺便向不是这行的老乡科普一下。 DB就是常说的Database，
中文叫数据库. 传统的数据库模型是E. F. Codd发明的Relational模型。
实现RDB(Relational DB)的软件管理系统，就是RDBMS， 比如ORACLE，
MYSQL， SQL SEVER， IBM DB2等。
RDB的查询语言基于Relational Algebra, 或Relationa Calculus，
相当于数学里的一阶逻辑。 SQL就是标准化的RDB的查询语言。
纯粹的SQL因为基于一阶逻辑， 所以不是图灵完备(Turing-complete)的。
但常用扩充的SQL是图灵完备的。
SIGMOD |
|
|
w*r
发帖数: 2421 | 12 基本没戏, 有些RDBMS每个连接就是一个 instance,基本没有RDBMS提供API可以把
instance里面的 step info抓出来. |
|
e***e
发帖数: 168 | 13 do the following and post the plan :
1.
explain plan for
select count(*) from TA a where a.col1=601;
2.
set lines 140 pages 1000;
3. check the plan
@?/rdbms/admin/utlxpls;
Do you see full table scan? If so, try this:
1.
explain plan for
select count(*) from TA a where a.col1=601 and a.col2 like 'ABC%'
2. check the plan
@?/rdbms/admin/utlxpls;
Do you see index access path?
If so, use hint to enable index access path used in the second query.
explain plan for
select /*+ index(TA index_name) */ cou |
|
p*********a
发帖数: 61 | 14 现在的 cloud 还不足以支持如此广泛的应用
就像上一个帖子提到的
为了做到广泛，最终就是走 rdbms 的老路
变得臃肿，性能平庸化
因为没有 magic，任何 solution 都有 cost
另外一个问题就是，有多少公司愿意自己买服务器+rdbms
还是把东西扔到 cloud 里 |
|
w*r
发帖数: 2421 | 15 performance performance performance
numeric based id is always the choice. ID should not carry info like state/
county, it is simple violation of normal form 1 .
use id as id, use state as state. do not mix your id with other info, if you
do that, go back to use IMS.VMS.ISPF.COBOL
numeric value as long as its range is big enough to hold data volume is
always the choice, regardless of RDBMS. all implementation of RDBMS uses
storage better on numeric value comparing to its offspring character type... 阅读全帖 |
|
v*****r
发帖数: 1119 | 16 Here are my understanding for discussion ;-)
Being relational basically means manipulating data in sets. A set is
orderless, which is typically implemented as heap table in rdbms.
In relational theory, the moment you enforcing ordering to data sets, you
are out of relational domain.
Oracle IOT or SQLServer CI are all non-relational features in rdbms to deal
with performance for specific scenarios. Given a well implemented heap table
, non-relational features should only applies to specific scena... 阅读全帖 |
|
v*****r
发帖数: 1119 | 17 The moment you enforce order, you lose the thing called "relation" and the
flexibility of being relational. One benefit of such flexibility is the
ability for SQL engine optimizer to transform/rewrite your query based on
the grows/updates of your tables especially in complicated SQL query to try
to adapt the plan to achieve best performance. Those transform/rewrite are
based on relational mathematical model which deals with relation (orderless
datasets).
Same in SQL, the moment the order by is a... 阅读全帖 |
|
y****9
发帖数: 144 | 18 My understanding till today: NOSQL is just a special purpose database (or
data model), it cannot replace traditional general purpose RDBMS. It has
little impact on DBA’s career.
Cloud computing provides additional choices for a company for its IT
infrastructure. Basically three choices: traditional in-house IT；
outsource IT totally ( i.e. to public cloud provider, pay-per-use );
consolidating in house IT infrastructure on private cloud; or maybe the
fourth choice, some kind of mixing of a... 阅读全帖 |
|
|
B*****g
发帖数: 34098 | 20 【 以下文字转载自 Java 讨论区 】
发信人: verde (没有你成), 信区: Java
标 题: Re: Job with Oracle PL?
发信站: BBS 未名空间站 (Wed Dec 21 06:21:14 2011, 美东)
scalability这个词是有context的，不同的context不能直接比较，
RDBMS和NoSQL是一个spectrum里面两个不同的position，直接
比scalability好比apple vs orange，恐怕不太合适。
选nosql还是rdbms完全是application domain的问题，和这两种技术
谁高谁低无关。
PL/SQL完全可以run 在cluster上，我不知道前面说pl/sql只能run在一个
machine上是怎么来的， |
|
B*****g
发帖数: 34098 | 21 不是group里的请看第二讲的Agenda
Agenda for May 9. Wednesday Oracle ????
9pm-10pm (ET) Technical Discussion
* What is RDBMS
* The Oracle implementation of RDBMS
* The responsibilities of Oracle DBA
* The Oracle technology that increases database availability
-- Backup/Recovery
-- Total Recall and Flash back Database
-- Cluster, RAC One, RAC, Data Guard
-- ASM (Automatic Storage Mangement)
-- Oracle Enterprise Manager
-- Golden Gate and Streams
10pm- 10:30(ET) Career Discussion
* The DBA MM
* Question and A... 阅读全帖 |
|
B*****g
发帖数: 34098 | 22 第二讲: Oracle 新手入门
时间: 五月九日，星期三，美东时间晚上9点
讲座者：Kevin Zou (Oracle Exadata/Bigdata Appliance Sales Consultant at
Oracle)
参加办法：全部免费，无需报名，讲座当天连接到网址http://www.AnyMeeting.com/cinaoug1 (Linkavailable after 8:50 PM)
Agenda for May 9.Wednesday
9pm-10pm (ET) Technical Discussion
* What is RDBMS
* The Oracle implementation of RDBMS
* The responsibilities of Oracle DBA
* The Oracle technology that increases database availability
-- Backup/Recovery
-- Total Recall and Flash back Database
-- Cluster, RAC One, RAC... 阅读全帖 |
|
c*****d
发帖数: 6045 | 23 另外一个DC附近的DBA工作机会
两周前收到的email，不过我已经从了芝加哥的一个offer
Hi coolbid– We received your résumé earlier this year as a referral from
miniID for an Oracle DBA opening that we have. This role as re-opened and I
wanted to present it to you. Below are the full details. Please review
and let me know if this is something you would be available and interested
in discussing.
Thank you in advance for your time!
We have an immediate opening for a Senior Oracle DBA for a long term (1+
year) opportunity supporting ... 阅读全帖 |
|
p***n
发帖数: 635 | 24 RDBMS doesn't have to be standardized but rather the languages used
by RDBMS could. |
|
x***n
发帖数: 39 | 25 When no exception is thrown, I assume your program was still trying to
talk to the RDBMS server. Check the network traffic by using some sort
of listening software such as ethereal or commview. At the same time,
try to replace the server with another one, or try using another RDBMS
such as using MySQL. Also you can try issueing a dummy select statement
and see if it works. |
|
s******n
发帖数: 876 | 26 There's a debate of focus between consistency and availability.
RDBMS as is provided strict consistency but poor availability.
We are entering an era where availability is king.
Sites like amazon and ebay must keep running every single second
of day while consistency can be relaxed with little loss of money.
Can't we have both consistency and availability? CPA theorem
claims that it's impossible; and real life experience with RDBMS
hints that it is very difficult.
Without relational model and tr |
|
w*********e
发帖数: 5286 | 27 Kernal RDBMS is way more complicated than what you said. The toy you implemented in school can not be called RDBMS.
optimizer, compiler, code generation, execution layer (serial execution,
parallel execution), data layer are much more complicated than what you
thought, not to mention transaction, materialized view, language support,
manageability, etc. |
|
F****n
发帖数: 3271 | 28 Most things you mention are not core of RDBMS
implemented in school can not be called RDBMS. |
|
j***i
发帖数: 40 | 29 Following the thread, I think both daisyy and whisper have answered your questions several times.
You just repeated asking the same question over and over regardless of
responses from others.
If you do not wanna read source code or textbooks, you can go over
"Architecture of a Database System"
a recent however terrific paper by Joe. Hellerstein and Michael Stonebraker.
Specifically, you can read Section 4 to understand what the core RDBMS is.
By no means you can implement the core logic of RDBMS |
|
v***e
发帖数: 2108 | 30 scalability这个词是有context的，不同的context不能直接比较，
RDBMS和NoSQL是一个spectrum里面两个不同的position，直接
比scalability好比apple vs orange，恐怕不太合适。
选nosql还是rdbms完全是application domain的问题，和这两种技术
谁高谁低无关。
PL/SQL完全可以run 在cluster上，我不知道前面说pl/sql只能run在一个
machine上是怎么来的， |
|
v***e
发帖数: 2108 | 31 谢谢，已经加入了。
看到自己在oracle rdbms做的新feature被你们讨论，来自第一线用户的
feedback，也有些启发。
Oracle RDBMS 12g会有一些massive scalability的东西出来。 |
|
i****e
发帖数: 913 | 32 Spring's use of unchecked data access exceptions is consistent with that of
many - probably most - successful persistence frameworks. (Indeed, it was
partly inspired by JDO.) JDBC is one of the few data access APIs to use
checked exceptions. TopLink and JDO, for example, use unchecked exceptions
exclusively. Hibernate switched from checked to unchecked exceptions in
version 3.
这是Rod讲解Spring JDBC的原话
http://www.theserverside.com/news/1364527/Introduction-to-the-S
大体意思是:
By wrapping JDBC check exce... 阅读全帖 |
|
l******t
发帖数: 660 | 33 为啥RDBMS is not build for dw and bi? 有几家公司用得起data warehouse
appliance的, 绝大多数都是用rdbms来当data warehouse, Oracle有那么多revenue
share, 就是因为买oracle来做dw的多,
According
top
you |
|
c****e
发帖数: 1453 | 34 That's because almost all use scenarios in Netflix don't care about
consistency that much. I bet they won't run the billing pipeline out of
RDBMS. Most likely, they still have to pay premium to Oracle to charge money
in a reliable way.
There are many aspects of big data. It just depends on your application. You
can even have MPP RDBMS. |
|
g*****g
发帖数: 34805 | 35 我再说一遍，NoSQL是确定RDBMS不够用的时候才用的，而不是反过来。
楼主那点东西，RDBMS哪点不够用？ |
|
g*****g
发帖数: 34805 | 36 从数据库实现的角度讲，NoSQL DB不见得比传统数据库更复杂。
但从开发者的角度来说，NoSQL比RDBMS复杂太多了。RDBMS大同小异，而常见的NoSQL
就有10个左右。挑一个合适的本身就很见功底。
reduce |
|
g*****g
发帖数: 34805 | 37 魏老师一脑子的浆糊，非要把客户下订单和订单处理放在同一个数据库里。
从丢人走向更丢人是不奇怪的。整个scalability的要素，本来就是把需要
transaction的数据单独拿出来，把不需要的拿到RDBMS外面去。再把
RDMBS根据数据耦合度尽量细分。
我老解释了这半天，魏老师连客户订单这个东西，不需要在RDBMS里都没弄明白，
踩他也实在没意思。实在连基础知识都没掌握。 |
|
g*****g
发帖数: 34805 | 38 也许我翻得不好，我的意思就是join。RDBMS常见性能问题之一就是在大表上的full
table join，另外在SOA上往往多个服务多个数据源，数据源本身可以是RDBMS也可以是
NoSQL。ES存储的是Json，这就可以让你整合多个数据源，根据下游用户的需求产生一
个可搜索的rich data set。相当是一个可搜索的缓存。 |
|
d****n
发帖数: 1637 | 39 瞎说一下啊，鄙人根本没经验。
除了content 以外的查询用rdbms,
content search 再另建一个nosql 用mapreduce 专门干这个。
这个非常适合read 多于write情况。
不好的地方就是额外的存储开销和save content 时候要建立 nosql delay
keyWords occur rdbms-indexId?
黄容 100 idx0
郭靖 85 idx17
避血剑 50 index 55
然后对 sentence 展开，我估计肯定有专门干这个的轮子，不用自己造 |
|
N********n
发帖数: 8363 | 40
说整个企业市场生态环境，SB憋了半天就弄出rdbms市场来。rdbms也就企业市
场1/10多一点，而且Sql Server早超DB2了。办公软件的市场哪家可以和微软
相比？SUN以前做StarOffice之后被甲骨文收购，现在生态系统咋样，竞争得
过微软吗？LOL. 企业级CMS有谁可以和Sharepoint竞争？有个开源Afresco
java写的吹破天。去网上看了一下，SP JOB有3000多，Afresco才70多。就这
逼样还叫板生态系统，真TM笑死人。
微软在企业界从数据库、到办公、CMS、VIRTUALIZATION、UC、CRM、CLOUD通
吃。整体生态环境业界无人比得上微软，也就你这号无知无畏SB出来叫板。 |
|
g*****g
发帖数: 34805 | 41 我看你还是再读一遍CAP theorem吧。NoSQL如果完全支持ACID，就跟RDBMS的属性一样
了，那还叫
NoSQL干啥。NoSQL就是跟ACID不兼容的。Berkeley DB能支持ACID本质上是因为是单机
系统，你来个多机的Berkeley DB还能支持ACID我就服。
RDBMS支持ACID，是CA系统，NoSQL可以是CP或者AP，两者在CAP theorem下是互补的，
不是冲突的。 |
|
g*****g
发帖数: 34805 | 42 所以虽然berkeley确实不是rdbms，但从cap角度看，跟rdbms就是一类东西。关键在于
取舍，而不在于实现的数据结构。nosql是coin name，不是什么严格定义，基本上就是
说非CA系统而已，不是非relational的意思。 |
|
k****i
发帖数: 101 | 43 Consistency, Availability, Partition-tolerance
RDBMS: favor C over A or P => CP, (CA unlikely if network unreliable)
NoSql: favor P over A or C => AP, (CP sub-optimal w/o normalized join)
NewSql: RDBMS 2.0
Mongo: NoSql-CP |
|
w**z
发帖数: 8232 | 44 RDBMS 和 NOSQL 本来就是互补的。谁说过nosql 包打天下？ 90％的case RDBMS 足够
了。但如果数据量大到一定程度，一定要Shard 的话，nosql 就有用了。shard mysql
多痛苦，做过的都知道。而且Cassandra cross DC replication 比mysql 之流的好用
无数倍。 |
|
d****n
发帖数: 12461 | 45 我觉得front end之所以难找是因为很多时候没法定量写需求，都是萝卜青菜连自动化
测试也不可能。
因为程序员花了大量的时间在手动测试的过程当中，而且因为需求不定量所以更改频繁
，而且每次更改以后测试基本又要手动来一遍，所以其实很多是无用功。而且框架再全
，有时候客户想要的功能偏偏在用到的框架上很难实现，但是在另一个框架上又很容易
，结果又是无用功切换。
你们有看到后端数据库整天从一个rdbms挪到另一个rdbms吗？看到后端程序员每天从一
套api捣鼓到另一套api吗？ |
|
t*******8
发帖数: 13 | 46 A financial technology firm is currently seeking smart people to join
their high performance, low latency electronic trading platform
development team. The company’s headquarter locates in New York’s
financial district, right next to the NYSE building. Please send your
resume to m**[email protected] if you are interested.
Opening one:
Job Title: Mid Level C/C++ Developer
Essential Experience:
• 2 or 3 years of experience in commercial software development in
C or C++
• A good working... 阅读全帖 |
|
e****x
发帖数: 692 | 47 我们家附近quant developer的职位不太多。大家觉得下面的2个job方向怎么样？现在
好像比较火
JOB 1
Machine Learning: We build and refine powerful machine learning models to
identify good and bad actors. These models automate decisions, prioritize
our work, and change the behavior of Square’s products in real time.
Underwriting: What qualifies a creditworthy merchant? How do their products
and services add value for customers? We place smart bets on great merchants
to grow our business and ensure a beautiful payment experience for our... 阅读全帖 |
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n****n
发帖数: 11 | 48 现在大家都说大数据，个人翻了翻一些资料，发现相关的内容大致有两类：
１－Map-Reduce：就是用所谓的Pig /Hive/Hbase来调用Hadoop系统里众多Cluster的一
个不断搜索，查询，分类和整理的过程。这个过程的性质和现在大家普遍所熟悉的ＳＱ
Ｌ功能相似，只不过是针对更大的量（PB/TB）和更复杂的结构（来自Web log/网络交
易/Social/甚至物理终端设备）。所以Map + Reduce就是个便于在这些数据中不断查，
不断合并的过程。
整理完的结果可以生成现在的RDBMS（彻底淘汰RDBMS是需要相当勇气的）。也就是说，
基本上，一旦数据整理完成，还是依然可以采用现在的方式来做模型，Predictive
Modeling, Scoring, Forecasting. 该怎么，就怎么，方法和程序不会太变化。尤其
是在金融行业，面对行业准则和政府法规，很难有大的变化在这上面。可能影响到的职
业或许会是：Business Intelligent, DBA, Database Programmer..etc 以数据准备
、整理和规范化作为主要职业的。这些是统计建模的... 阅读全帖 |
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c******y
发帖数: 3269 | 49 The two datasrcs refer to two types of RDBMSs?
In this case, if one of them supports dblink (for example, Oracle), then you
can do it within that RDBMS.
If they are two databases or schemas within the same RDBMS, then you usually
can give the full path, e.g. database.schema.table, to join them |
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G*******9
发帖数: 4371 | 50 【 以下文字转载自 WashingtonDC 讨论区 】
发信人: Great2009 (栀子园主，诚招助手), 信区: WashingtonDC
标 题: DC在招IT工 ActioNet Positions。。。
关键字: IT 招人 ActioNet Positions Openings
发信站: BBS 未名空间站 (Sun May 25 21:23:16 2014, 美东)
我在帮朋友的朋友发帖，你可以发包子给我表示感谢，但是请不要问我更具体的问题。
呵呵。。。
ActioNet supports the Centers for Medicare and Medicaid Services in key
areas of health IT solutions delivery. We are looking for Java Developer (
all levels) and System Analysts (all levels) with experience at CMS, Health
IT, or similar systems development en... 阅读全帖 |
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