a*******t
发帖数: 891 | 1 There are no clustered index on the tabled I tried.
I tested on 1 of the 20 or so non-clustered indexes. |
|
a*******t
发帖数: 891 | 2 yes.
I am thinking the alter index rebuild doesn't actually drop the index, it
scans and don't touch the pages if it's still good? |
|
a*******t
发帖数: 891 | 3 day 1, drop, create, 2 hr
day 2, alter index rebuilt, 15 min
day 3, drop, create, 2 hr
no data change in between
and keywords in my original post: according to BOL and TechNet, alter index
rebuild = drop + create |
|
j*******7
发帖数: 6300 | 4 也许逻辑上等价，但rebuild实际上并行建立那些index,而drop+create是串行执行？值
得研究。
Also I find the BOL says there are log differences per recovery models and per different index operations. |
|
i****a
发帖数: 36252 | 5 need to query between TableA and TableB. and it's taking too long
because the columns on lookup do no have indexes
TableA.CustNum data can appear in any or all of the following columns in
TableB
TableB.CustNum1
TableB.CustNum2
TableB.CustNum3
about 240M rows in TableB, on index on the CustNum fields, no foreign
keys
I am thinking creating a separate table with only 3 CustNum1/2/3
columns, with indexes defined, then insert 3 columns of data into it.
but it takes 20 hours to insert with indexes de |
|
U****D
发帖数: 113 | 6 Thanks.
We have a 800G database. The administrator set the reorganize/Rebuild index
once a week. It takes more than 2 hours to reorganize index and over 8
hours to rebuild index. Is there a way to shorten the time? |
|
y****9
发帖数: 144 | 7 I have read "As a rule of thumb, every table should have a clustered index"
(see http://www.sql-server-performance.com/2007/clustered-indexes/ )
Isn't this a really general rule? Do your production database tables follow
this?
If I understand correctly, this feature corresponds to "Index organized
table" (IOT) in Oracle, generally IOT could be good for look up talbe in
Oracle.
But I have never seen similiar recommendation in Oracle. Interested in
knowing why or whether it is really good to have ... 阅读全帖 |
|
v*****r
发帖数: 1119 | 8 You understanding is right, Oracle IOT serves the same purpose as clustered
index in SQLServer (only difference is you can view IOT is PK only clusted
index). Whatever advantage and disadvantage to use IOT applies to clustered
index in SQLServer, so obviously, it is NOT true "As a rule of thumb, every
table should have a clustered index".
"
follow |
|
c*****d
发帖数: 6045 | 9 第一，如果每个index都只能建在单个column上
index_1 shows last_name='xxx'的记录有第1，3，5，7，9行
index_2 shows email='yyy'的记录有第3，5行
这两个如果是btree index没法做交集操作
bitmap index可以
第二，这个问题想解决请google composite index |
|
c*****d
发帖数: 6045 | 10 bitmap不是一种join方式，他只是一种索引，只不过支持and/or/not
query planner会根据具体索引结构建立最佳方案，选择最佳的一个index
但是，你没办法让两个btree index作and/or/not
在你这个例子中，可以创建单独last name字段的索引，或者email上的索引，或者(
last_name,email) or (email, last_name)上建立composite index，如果你创建了这
些索引，当然storage上是浪费了，但是提高了查询效率。我们很多表都是5-10个索引
INDEX |
|
j*******g
发帖数: 6 | 11 【 以下文字转载自 Hardware 讨论区 】
发信人: jerryking (Tiger), 信区: Hardware
标 题: 为什么同样的显卡,不同的windows experience index?
发信站: BBS 未名空间站 (Fri Mar 30 01:46:21 2007)
Compaq v6000 laptop, intel GM950 video card, windows vista experience
graphic index 2.2
Toshiba laptop, same intel GM950 video card, windows vista experience
graphic index 3.0
Other things(CPU, Memory) are similiar, why so much difference in graphic
index? |
|
j*******g
发帖数: 6 | 12 【 以下文字转载自 Hardware 讨论区 】
发信人: jerryking (Tiger), 信区: Hardware
标 题: 为什么同样的显卡,不同的windows experience index?
发信站: BBS 未名空间站 (Fri Mar 30 01:46:21 2007)
Compaq v6000 laptop, intel GM950 video card, windows vista experience
graphic index 2.2
Toshiba laptop, same intel GM950 video card, windows vista experience
graphic index 3.0
Other things(CPU, Memory) are similiar, why so much difference in graphic
index? |
|
p********0
发帖数: 186 | 13 HI,
I have a question about the index fund,
Assume the index fund contains 2 stocks without loss of generality,
STOCK 1, market_cap 1 million
STOCK 2, market_cap 10 million.
So the Index fund will buy X values of STOCK 1, and buy 10 X values of STOCK
2,
with the values proportional to the MARKET_CAP of individual.
Is this correct?
Or Index fund buy same X values for both STOCK 1 and STOCK 2.
Thanks |
|
h*******n
发帖数: 24 | 14 Do you guys have any idea about which is better, index or market maker?
In my company, most of ppl trade stock options - American and Vanilla. So
option trading is basically market making.
Index trading does not make markets. We trade index futures and hedge by
either basket or another index futures, which is kind of spread trading.
I might be able to choose which desk to work for. So I'm really keen to the
anwser~ Thanks man. |
|
c*****a
发帖数: 808 | 15 data loop;
x = 0;
index=1;
do until (index =5);
index+2;
x = index ;
end;
run;
proc print data=loop;run;
? |
|
g********n
发帖数: 2314 | 16 唱衰的：
S&P/Case-Shiller: Housing Prices Mostly Declined In November
Yesterday, I wrote about the big existing home sales decline in December.
Today, another important housing market metric was released: the S&P/Case-
Shiller Home Price Indices for November. The news here isn't any better here
. Both, its 10-city and 20-city composite price averages were down in
November. Prices were down for 16 of the 20 metropolitan areas it tracks.
The indices trend isn't encouraging.
Here's how the month-over-m... 阅读全帖 |
|
|
k**1
发帖数: 1955 | 18 Index is difficult to measure. However, if you know radius on both sides of
the lens and center thickness, you can use ZEMAX to simulate the edge
thickness of the certain size of glasses and its index of refraction. That
will be very accurate
If you have astigmatism, it will be more difficult.
A senior optical engineer.
“ high index的主要目的是看的更清楚，而不是更薄。” this is a wrong
statement, this person cannot work in that shop. |
|
m**********e
发帖数: 12525 | 19 太鸡巴搞笑了
什么health index,妈的,什么叫health index? 还不是你上下两张嘴
随便说的么
只有GDP是硬指标,丫不敢比,就敢叽歪什么health index |
|
t*******c
发帖数: 306 | 20 【 以下文字转载自 EE 讨论区 】
发信人: tieshouzc (tieshouzc), 信区: EE
标 题: us semiconductor index从16年初开始暴涨啊
发信站: BBS 未名空间站 (Thu Oct 26 14:45:15 2017, 美东)
us semiconductor index从16年初开始暴涨啊！google 搜us semiconductor index可
以看到，怪不得今年USC EE vlsi new grad都找到工作了！ |
|
y********e
发帖数: 181 | 21 不是大牛的说
H-index那个东西是分专业的，通常在物理领域。如果你的搞计算机，说什么H-index就
有点儿那什么了...
另外，如果你的名字是popular的那种，你的H-index会很高，呵呵 |
|
|
c******a
发帖数: 633 | 23 H-index就一数字，数字码当然有水分。
回答你的问题：
H-INDEX 计算的时候包括自引么？yes
自引文章是如何加权计算的，和他引是一样处理
的么？yes
它计算的时候区分第几作者么？no
不过看/算H-index的人都不傻^-^ |
|
|
y****t
发帖数: 10233 | 25 1) 长远来看,很少有一个fund or sector has beat the index.
这句话本身没有错.但是你忘了,没有一个active management的人会抱住一个fund或
sector不放的.他要是真的这样做了,就变成passive management了.
所以更准确的说这句话就是,如果你要准备paasive management, 没有比Index 更好的
了.
fair enuf.
2)混淆market的概念.
当开比的时候,总拿sp500来说事,可一但不顶了,就开始讨论risk和asset allocation.
这本身不就是active management吗? 我问你,你的risk怎么定啊?你的weight是多少啊?
一辈子就不变了. 他index本身这么多年还在变呢. 你所做的就是跟着ws的大牛砸钱,他
们砸向哪里,你就砸向哪里,当然我不是说this is a bad idea.
所以说,没有一条清晰的线划出active or passive.很多人都落在了中间.鼓吹一个好过
另一个都是不make sense的.根据你的情况做出适合你的投资,并调整策 |
|
t***s
发帖数: 163 | 26 我一定奉陪到底
1. Portfolio management 和 index investing是两回事
Portfolio design讲究的就是asset allocation，确定
asset allocation要看你的投资目的和risk tolerance
投资的目的不是最大化return，而是达成finacial goal（退休）
不根据自身risk tolerance设计portfolio最后在bottom
bail out结果不言而喻了
Portfolio management当然要active management，比如
随着年龄增加降低风险，rebanlance等等
一旦asset allocation确定了，买进asset的时候
就只有一个选择了：index fund
在每一个asset里index fund和activemanaged fund的
比较就不用说了，结论请google
2. market只有一个，即全球的资本市场
包括所有自由交易的stock，bond，Real estate。
如果投资者没有risk tolerance和投资年限的限制。
E |
|
s******d
发帖数: 323 | 27 ☆─────────────────────────────────────☆
yourtt (rainmaker) 于 (Fri Dec 1 01:27:44 2006) 提到:
index investing are for average joes.
it's safe because indexes are created by market makers to benchmark the
market. the market has to go north, so this bench mark has only one way to
go in the long term. Because of the inflation, and because north is
necessary to have this monster suck in more money to backbone the market
confidence.
market makers dont give a damn on indexes, they rotate their mone |
|
s******d
发帖数: 323 | 28 ☆─────────────────────────────────────☆
nihuai (DULM) 于 (Tue Dec 12 03:26:35 2006) 提到:
很简单。
优点：
1). Low cost. Index fund的expense ratio 在0.2%, MFs的平均expense ration是1.
36%.
2). 简单。半年或一年看一次就行了。
3). turn over小，少交税。
缺点：
1). No way to out-perform, 扣掉cost, 你的回报比市场只小一点，很接近啦。依然
逃不掉市场崩溃的风险。想像
你买了index fund when nasdaq is at 6xxx.
2). a little bit extra small cost: index fund 要买掉被delisted的股票（价格在
跌），买如新加进来的股票（价格
高）
下面我要说的很重要啊，大家要记笔记了！
“Economists cite the efficient market theory as the fundamental pre |
|
s******d
发帖数: 323 | 29 ☆─────────────────────────────────────☆
yourtt (rainmaker) 于 (Wed Feb 14 15:42:12 2007) 提到:
1) 长远来看,很少有一个fund or sector has beat the index.
这句话本身没有错.但是你忘了,没有一个active management的人会抱住一个fund或
sector不放的.他要是真的这样做了,就变成passive management了.
所以更准确的说这句话就是,如果你要准备paasive management, 没有比Index 更好的
了.
fair enuf.
2)混淆market的概念.
当开比的时候,总拿sp500来说事,可一但不顶了,就开始讨论risk和asset allocation.
这本身不就是active management吗? 我问你,你的risk怎么定啊?你的weight是多少啊?
一辈子就不变了. 他index本身这么多年还在变呢. 你所做的就是跟着ws的大牛砸钱,他
们砸向哪里,你就砸向哪里,当然我不是说this is a |
|
K****D
发帖数: 30533 | 30 假设某一天开始所有的投资者都成了total market cap weighted indexer,
(这个是假设，所以偶主观决定采用这种index) 并且随机制定DCA的入场时间，
那么会发生什么呢？
1) CNBC，bloomberg, finance.yahoo.com, morningstar等等一周后关门。
Cramer改做standup comedy.
2）所有指数按照10%/year左右的速度平滑上涨：美国变快，中国变慢。
3) 某外国公司一年前靠做假账创造了空前高涨的股票价格，但是目前其假账
被揭发。CEO一筹莫展坐在写字台前发愣。这时候秘书进来了：老总，表怕，
自从事发以来，俺们公司的股票仍然保持着以前的良好势头，钱还在不停
的涌进来，根本就没有人关心俺们的丑事！CEO顿时喜笑颜开。
4) 3个月以后16.2%的工人每个礼拜至少旷工2天。
5) 半年后27%的employee开始被扣工资。
6) 所有指数开始按照-25%/year的速度下滑。
7) CNBC重新开张，Cramer当上台长，并花两周时间呼吁大众停止indexing.
8) 指数开 |
|
s********n
发帖数: 1962 | 31 ☆─────────────────────────────────────☆
straw (berry) 于 (Sat Apr 19 00:39:57 2008) 提到:
If I enter the market on Jan 10, 2000 (with Dow 11722),
then on the date of march 10, 2008 (with Dow 11740),
I earn almost nothing?
So the key is DCA for indexer?
thanks.
☆─────────────────────────────────────☆
Taikonaut (遨游太空) 于 (Sat Apr 19 00:52:04 2008) 提到:
铁杆indexers快来回答问题
我这个候补indexer就在一边旁听了。
☆─────────────────────────────────────☆
straw (berry) 于 (Sat Apr 19 11:12:52 2008) 提到:
要不您这个优秀生先说说 |
|
t*******y
发帖数: 11968 | 32 http://online.wsj.com/article/SB124036618955342011.html
By SAM MAMUDI
NEW YORK -- Investors in actively managed mutual funds for the past five
years have reason to wonder what they have been paying for: A new study from
Standard & Poor's finds that 70% of large-cap fund managers who use the S&P
500-stock index as a benchmark for comparison have failed to match the
performance of the index over that time.
Discuss
That is double-bad news, given that the index was down 19% in the five years
that en |
|
P***i
发帖数: 44 | 33 I am being approached by a sales person about this product inside life
insurance. It seems to be too good to be true.If the index drops, it gives a
guaranteed interest rate of 1%. If the index increases, it gives the same
interest rate as the percentage of index increase with a cap of 13.25%.
When it is too good to be true, it is very likely not true. Any comment on
this product is greatly appreciated.
BTW, is there a similar product available for the public to invest in, but
outside life insura... 阅读全帖 |
|
X****r
发帖数: 3557 | 34 Tracking an index accurately is non-trivial. Quoting William Bernstein
in "The four pillars of investing":
'This gets to an important issue, so-called "transactional skill."
Itis often said that a monkey could run an index fund. Nothing could
befurther from the truth. Precisely tracking an index requires a
veryhigh degree of market savvy, discipline, and nerve.'
That said, I suspect a significant portion of the cost comes from
running the business itself, i.e. administrative costs, like record... 阅读全帖 |
|
s*****e
发帖数: 21415 | 35 主要原因是active managed fund有fee，比passive要高不少。
所有active managed fund collectively，他们的alpha是一个零和游戏，考虑到fee，
就是一个负和游戏。
所以after fees, 80% lose to index并不奇怪。
我猜测，如果没有fee，可能50% win against index, 50% lose to index。 |
|
s********n
发帖数: 1962 | 36 You are assuming you know when it's a bear market and when it's
a bull market in advance, while indexers assume you can never know.
Look, don't assume others are stupid. Do you really think if an
indexer knows for sure the market will drop, he/she will still
buy into any index? |
|
S**C
发帖数: 2964 | 37 Those studies have something in common, they compare the whole active funds
universe and equal weight, which are intellectually lazy and dishonest. Any
investor who do his or her DD won't invest that way. Or you try to tell me
ER and AUM has no signifivant negetive impact on TR? Or anyone should be
surprised that closet-index funds will underperform, given they closely
mirron index yet charge higher fees?
Actually I love to see people move to index funds, it is of my interest for
at least two re... 阅读全帖 |
|
w***n
发帖数: 1519 | 38 你确定看明白你给的这个链接了？这里边的所谓“各Index”，除了SP600是mid cap之
外，其它几个不都是small cap吗？
“Dispersion of returns is not as considerable an issue with Total Market
indexes, but as we go into style and smaller size indexes, dispersion of
return increases in magnitude.”
了. |
|
p**h
发帖数: 1105 | 39 CREF equity index = TIEIX??
TIAA-CREF Equity Index Fund is an open-end fund incorporated in the USA. The
Fund seeks a favorable long-term total return, mainly through capital
appreciation, by investing primarily in a portfolio of equity securities
selected to track the overall U.S. equity markets based on the Russell 3000
Index.
如果你指的是这个MF,它追踪的是 Russell 3000 （RUA）.现在所有大盘指数都是 all
time higher, Russell 3000 也是如此， YTD return 都超过或接近20%了。 不过
high 可以 higher， 谁知道到了 12/31/2013， 2013 会是 1987年（high -> low)... 阅读全帖 |
|
w******1
发帖数: 154 | 40 我的退休账户是fidelity 的，Spartan 500 Index Fund 的expense ratio是0.07%，
freedom 2045的expense ratio 是0.78%。看了一个纪录片，说30年后fees会相差非常
多。比如我算了一下，30年后这两个fees会差10倍。所以想换成Spartan 500 Index
Fund，或者放到vangard 里。想问一下，fidelity能换吗，或者转出来吗？怎么做？我
要全部都换成index吗？我是要长期投资的。
看了很多帖子，精华也看了，太晕了！ |
|
s*******e
发帖数: 257 | 41 哈哈，谢谢指点。以前真是什么都不懂，现在稍微懂一丁点，要卖掉一大堆fund又怕做
错了。
关于investment，我看大部分的建议都是不要去time market，保持asset allocation
就好了。可是现在index一再创新高，不知道啥时候会大跌。现在进index会不会进在高
点了？是不是还不如等大跌以后再进index？我简单读了一下Faber's approach，觉得
是不是更可行，hold到一定程度就cash out，然后在低点再进。不知道大牛有没有试验
过？对我们这样的新手来说，是不是就dollar average+rebalance就够了。 |
|
w********0
发帖数: 245 | 42 没有投资过，也没有买过股票，我就只懂得存钱进money market account,然后这两个
月开始看一些理财的书，针对我这种新手以及极端保守的也没几个钱的人，好像index
fund大家都比较推荐,看来看去好像vanguard s&P index fund大家都比较推荐。
这种一般需要需要注意什么？是不是就注意收费情况？
是不是开户了后，就把钱放里边，然后等上3， 5年再取回，打算过几年买房子呀？
没有做过，打算明天打vanguard的服务电话问问800-252-9578
https://investor.vanguard.com/mutual-funds/index-funds?WT.srch=1
能否请版上的高手指点一下。 多谢了 |
|
q****4
发帖数: 226 | 43 如题，请问买这种internaitonal index fund风险很大吗？有人说还是只买US stock
index,买international 风险太大。。
已经买了fidelity small, mid，large cap的index funds，FSSVX, FSCKX, FSTVX来分
散风险，但都不是很多（各$10k吧），穷人一枚，虽钱不多，但也不想打水漂了呀，所
以请班上大大们看看：
有必要再买international 的 FSIVX 来更加分散下风险吗？ 或者干脆追加到已买的其
中一种？
谢谢！ |
|
a********e
发帖数: 547 | 44 我咨询了一个Voya 的人，他说他不推荐index fund, 因为很多别的基金比index fund
收入高。非 index fund 的风险到底在哪里？
我看到有个retail 领域的基金，这些年上涨非常好，长期短期的都好。可是我读的那
本书说，除非你熟悉那个领域，否则不要买那个领域的基金。给投资公司的advisor 打
电话，他们也是这个意见。
我不太明白，所有的这些mutual fund 都是有人管理的。fund manager 有足够的
incentive 让资金赚钱。我的钱也和很多别人的钱一起被fund manager 管着，为啥
sector specific 的基金就比别的基金风险更大呢？
一个可能的原因就是整个retail 领域都从此萧条，一蹶不振。我是考虑了传统retail
被电商冲击大。可是我看了它投资的对象，不光有传统的retail， 也有internet
retail, 比如Amozon 之类的。
是不是这个原因呢？：不管实际上会怎样，只要很多人认为retail 完了，都把钱抽走
。而我一个不懂的人，或者不怎么经常关注基金动向的人钱还在那里，就会可能遭受重
大... 阅读全帖 |
|
m*********t
发帖数: 1250 | 45 我算是Bogleheads的投资理念拥护者之一，个人理解是买index是基于成熟的市场环境下
以机构投资者为主导高效率市场的投资策略，大部分投资人基于长期投资的规划可以满
足基于此的Market Average Return。而相反的极端例子可能就是国内的A股市场，以散
户主导，信息不透明，追涨杀跌短期投机行为为主，所以可能并不适合index策略。
基于上面的理解，我个人觉得在以Index investing为主的策略下，追求短期high retu
rn为目标适当配置一部分Active Fund （如一些Dividend Growth）或如P2P之类的新As
set Class，也并不冲突。
mutual |
|
d******a
发帖数: 32122 | 46 按照股票市场index组合的，很容易理解
但是bond是这样的，比如你买的本金是100块，一年后会返还本金加利息 100 + 1 块。
一年后，bond index变成 98快了，我是拿到 100 +1 还是 98 + 1？ 我看到的这些以
bond index组合的mutual fund, 收益率是负的，难道真的是给 98 + 1? |
|
N******o
发帖数: 3053 | 47 一年后，bond index变成 98快了，我是拿到 100 +1 还是 98 + 1？
我的理解，你买的本金是100块在bond index 100的时候，一年后，bond index变成 98
快了，那么你是拿到98. |
|
|
s*******m
发帖数: 228 | 49 出了一个inverted index的题，就是有一大堆doc，对doc里出现的word建inverted
index，doc很多所以是distribute在很多machine上的，问怎么实现这个inverted
index |
|
t*******c
发帖数: 306 | 50 【 以下文字转载自 EE 讨论区 】
发信人: tieshouzc (tieshouzc), 信区: EE
标 题: us semiconductor index从16年初开始暴涨啊
发信站: BBS 未名空间站 (Thu Oct 26 14:45:15 2017, 美东)
us semiconductor index从16年初开始暴涨啊！google 搜us semiconductor index可
以看到，怪不得今年USC EE vlsi new grad都找到工作了！ |
|
