l******t
发帖数: 660 | 1 你的意思是query的时候做 data base denomalization吧？ 就是join fact table和
dimension table成一个大的data set， 这个都是query time或者 单独一个view，要
是都pre populate成为一个大table， 就失去了star schema的意义 |
|
c*********e
发帖数: 16335 | 2 比如一個star schema,要把各个dimension table的数据拷贝到fact table里面，拷贝
完后，就只对这个fact table做各种query. |
|
l******t
发帖数: 660 | 3 你的意思是query的时候做 data base denomalization吧？ 就是join fact table和
dimension table成一个大的data set， 这个都是query time或者 单独一个view，要
是都pre populate成为一个大table， 就失去了star schema的意义 |
|
y*****g
发帖数: 677 | 4 这个可能没什么原因。 如果你的TABLE很大，比如几十，几百G的话，是得花几分钟，
十几分钟的。可能是一个BUG IN INNODB.
For insert, 原因可能和你的table and indexes related.
贴 出来看看INSERT STATEMENT 和 TABLE DDL |
|
n****e
发帖数: 1403 | 5 (1). In database A, table `client`
CREATE TABLE `client` (
`pin` INT(11) NOT NULL,
`create_user` INT(11) NULL DEFAULT NULL,
`update_user` INT(11) NULL DEFAULT NULL,
`update_time` TIMESTAMP NOT NULL DEFAULT '0000-00-00 00:00:00',
`dob` DATE NULL DEFAULT NULL,
`create_time` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE
CURRENT_TIMESTAMP,
`dob_type` INT(11) NULL DEFAULT NULL,
`ethnicity_code` VARCHAR(10) NULL DEFAULT NULL,
`gender_code` VARCHAR(10) NULL ... 阅读全帖 |
|
d*******n
发帖数: 109 | 6 this is a single table query,
table looks like this:
column1 column2 column3 column4
1 0 1 0
0 1 1 1
1 0 0 0
1 1 1 1
...
four columns, each can be 1 or 0,
write one SQL query to get output looks like
TotalRow Count1 Count23 Count4
total row is the total row of table
count1 is the count of all row which column1 = 1 and the rest 3 columns are
0
count23 is the count of all row which... 阅读全帖 |
|
l******9
发帖数: 579 | 7 【 以下文字转载自 Quant 讨论区 】
发信人: light009 (light009), 信区: Quant
标 题: SQL multiply all values of a column in table
发信站: BBS 未名空间站 (Wed Jun 25 17:35:13 2014, 美东)
I need to multiply all float values of a column in table if the column value
is positive. If I find a value is null or negative or not numeric, I raise
an error in SQL server 2008 R2.
given table t0:
col
1.5
2
given table t1:
col
2
-1
5
0
null
NaN
For t0 I should get 3, for t1, I should raise an error.
... 阅读全帖 |
|
l******9
发帖数: 579 | 8 【 以下文字转载自 JobHunting 讨论区 】
发信人: light009 (light009), 信区: JobHunting
标 题: SQL combine two columns from two different tables no shared columns
发信站: BBS 未名空间站 (Fri Jun 27 12:46:58 2014, 美东)
On SQL server 2008, I need to get a new table by selecting two columns from
two different tables.
address (from another_table) id_num (from a cte created by me)
city_1 65
city_1 36
city_2 65
city_2 36
city... 阅读全帖 |
|
k**n
发帖数: 3989 | 9 比如有table A 有columns 十多个。
新table B有5个columns
这俩表是 （B）0-1：1（A）关系。
我要写一个GUI update table B,
看到要求是去掉B, 把B的5个columns都加到A上。
请问这样做有什么好处？
个人不喜欢太多columns的table设计。 |
|
n***l
发帖数: 143 | 10 In SSMS, click on the database, then database diagrams, choose create new
database diagram. Add the table of interest, then right click on that table
to add the related tables.
My question is how to quickly figure out the relationships if the database
has over 5000 tables? |
|
c*o
发帖数: 70 | 11 Recently, I found it div has so many advantages than table. It gave me a lot
of headache by using table especially complex table-in-table to arrange web
layout. Lots of my time was spent on that. Thanks to DIV, all problem are
solved. Hope this experience can help other persons who don't know it. Any one
can tell any shortcomings of DIV? |
|
y********o
发帖数: 2565 | 12 Disclaimer: I am not familiar with ACCESS at all. I just googled a little
and found the info below at http://office.microsoft.com/en-us/access/HP051876231033.aspx
Hide View or refresh links
Use this procedure to view or to refresh links when the structure or
location of a linked table has changed. The Linked Table Manager lists the
paths to all currently linked tables.
1. Open the database that contains links to tables.
2. On the Tools menu, point to Database Utilities, and then click Li |
|
z****e
发帖数: 2024 | 13 你这点说得非常对，map里边有iterator，是可以按顺序遍历的，hash 无法排序，无法
选择（比如第ith smallest）。
我还加一点，就是dynamic hash table. 因为事先不知道元素多少，无法确定table大
小，只能用table被填满一半，就把table大小翻倍，（linear probing 情况下）。这
个操作比较昂贵。用separate chaining 的话，元素越多，就越来效率越低。说是O(1)
的操作，最后都不知道O几了。
所以，不知道大小，就RB-tree，实现动态调整大小，而且，插，删，找，永远log(N)。
不知道这样说对不对，还有没有其他补充。
多谢大家。 |
|
l******9
发帖数: 579 | 14 【 以下文字转载自 Database 讨论区 】
发信人: light009 (light009), 信区: Database
标 题: Truncation error import csv file to SQL table
发信站: BBS 未名空间站 (Wed Apr 29 15:28:46 2015, 美东)
I would like to import a .csv file into a SQL Server 2008R2 database table
on Win 7.
It has one column and one row.
File1:
name
runeocnu 430274 sjunosnv djduenvop 934m ljfonm3
I got error:
Error 0xc02020a1: Data Flow Task 1: Data conversion failed. The data
conversion for column "NAME" returned status value 4 and status text "Text
w... 阅读全帖 |
|
a********n
发帖数: 648 | 15 总共有三个table，table后面是Reference，前两个table都没有问题，第三个table总
是跳到Reference后面，不知道是什么问题。刚开始用Latex，不知道有没有遇到过同样
问题的人能帮忙回答一下这个问题。谢谢。 |
|
l******9
发帖数: 579 | 16 【 以下文字转载自 Database 讨论区 】
发信人: light009 (light009), 信区: Database
标 题: sort two same tables SQL but different results
发信站: BBS 未名空间站 (Fri May 9 09:57:41 2014, 美东)
I am sorting two tables on SQL.
The two tables have the same column names and types and rows numbers.
I used order by to do sorting but the two tables are different in order.
Example,
SELECT *
FROM table1 AS t1
ORDER BY t1.col1 , t1.col2, t1.col3, t1.col4 ASC
SELECT *
FROM table2 AS t2
ORDER BY t2.col1 , t2.col2, t2.col3, t2.col4 ASC
T... 阅读全帖 |
|
l******9
发帖数: 579 | 17 【 以下文字转载自 JobHunting 讨论区 】
发信人: light009 (light009), 信区: JobHunting
标 题: SQL combine two columns from two different tables no shared columns
发信站: BBS 未名空间站 (Fri Jun 27 12:46:58 2014, 美东)
On SQL server 2008, I need to get a new table by selecting two columns from
two different tables.
address (from another_table) id_num (from a cte created by me)
city_1 65
city_1 36
city_2 65
city_2 36
city... 阅读全帖 |
|
o******6
发帖数: 538 | 18 ☆─────────────────────────────────────☆
largetail (largetail) 于 (Mon Mar 16 22:57:50 2009) 提到:
Any one familiar with hash table or handle large dataset (hundreds of
millions of obs) in SAS (sort merge and subset). Any reference and suggest
is greatly appreciated.
☆─────────────────────────────────────☆
qqzj (小车车) 于 (Mon Mar 16 23:46:54 2009) 提到:
hash table is used when you have a huge data base and a small code table.
you can transform the smaller one into a hash table. it is very effi |
|
i******r
发帖数: 861 | 19 table A:
x1 x2 x3 x4
1 5 6 9
3 4 6 1
8 2 2 1
...
tabl B:(每个column只有一个值)
a1 a2 a3 a4
0.1 0.2 0.15 0.3
用a1×x1, a2*x2, a3*x3,a4*x4,相当于给x1-x4加权。用merge两个table可以，但是我
有1000个variable，有什么好办法吗？两个table间的操作已经困扰我近一年了。 |
|
e**p
发帖数: 4259 | 20 刚刚自学学会用excel pivot table,但复杂一些功能不会，比如说我建立一个look-up
table,大概是这样的
COUNT Label
AA AUSTRIA Austria
AA BELGIUM Belgium
AA BULGARIA Bulgaria
AA CZECH Czech
AA DENMARK Denmark
AA FINLAND Finland
AA FRANCE France
.....
.....
我要跟另外一个table 联系起来
CTRY AREA UNITS
AA AUSTRALIA ASIA/AFRICA/AUST/ME 31,566
AA AUSTRIA WESTRN EUROPE/CANADA 28,046
AA BELGIUM SA WESTRN EUROPE/CANADA 72,138
AA CANADA WESTRN EUROP... 阅读全帖 |
|
l******9
发帖数: 579 | 21 I need to check the likeness between two data tables on SQL. I am working on
Aginity Workbench for Netezza on Win 7.
The tables are very large. One of them has 100 million rows and 4 columns;
another one has 1500 million rows and 3 columns.
Example, table1
ID1 ID2 ID3 Value
xxxx xxxxxx xxxxxxxx xxx.xxxxxx // here x is 0-9 int
table2:
ID1 ID2 Value
xxxx xxxxxx xxx.xxxxxx
the ID1 and ID2 may be duplicated but Values are not duplicated in the sam... 阅读全帖 |
|
l******9
发帖数: 579 | 22 【 以下文字转载自 Database 讨论区 】
发信人: light009 (light009), 信区: Database
标 题: sort two same tables SQL but different results
发信站: BBS 未名空间站 (Fri May 9 09:57:41 2014, 美东)
I am sorting two tables on SQL.
The two tables have the same column names and types and rows numbers.
I used order by to do sorting but the two tables are different in order.
Example,
SELECT *
FROM table1 AS t1
ORDER BY t1.col1 , t1.col2, t1.col3, t1.col4 ASC
SELECT *
FROM table2 AS t2
ORDER BY t2.col1 , t2.col2, t2.col3, t2.col4 ASC
T... 阅读全帖 |
|
b********1
发帖数: 291 | 23 好不容易造个回归模型，各项指标看起来很美，f, g, p, a, o 各项指标都通过, lift
curve, gains chart看着也不赖，以为没事儿了。 忽然老板说还要比较observed
value/predicted value. 于是我又在output 里面用个 p= option
proc freq ;
f_dv *i_dv /list missing;
title compare predicted value vs observed value;
run;
结果实际值与预测值完全对不上，差的十万八千里。 于是有用了ctable, 生成
classification table, 才发现我的这个table确实不太对劲。 我以往做的
classification table，sensitivity vs specificity 都能在classification 里面 [
.4 ~.6] 同时达到最高，大概70% ~80%. 可今天的table, sensitivity从100%立刻降
到40%以下，specificity 直接从0飙升到94%.
奇怪的是我的... 阅读全帖 |
|
s********1
发帖数: 235 | 24 【 以下文字转载自 Database 讨论区 】
发信人: someone111 (some), 信区: Database
标 题: 如何把一个correlation matrix 按照一个table 输入一个 database 里？
发信站: BBS 未名空间站 (Tue Dec 8 16:13:07 2015, 美东)
如何把一个correlation matrix 按照一个table 输入一个 database 里？有大约1000,
000 X 1000, 这么多vectors ，每一对vectors 算一个 correlation, 要输到database
的表里，每一个vector 都有一个常量string 对应，所以不牵扯把vector 输到
database table 里。怎么弄比较好？主要以后可能要拿这些代表 vector 的常量
string 做key join table. |
|
w**********a
发帖数: 107 | 25 I have a question on excel pivot table.
Here is my data set
Company profit
A 1
A 1
A -1
A -2
A 3
B 1
B 1
B 1
C -2
The pivot table I need is as follows:
Positive
A: 1
B: 3
Negative
C: -2
The pivot table I can get is
Positive
A: 4
B: 3
Negative
A: -3
C: -2
How do I net company A in pivot table?
Thanks a million! |
|
w*r
发帖数: 2421 | 26 Yes, it is working properly.
Test case:
Step 1 : create a python script to generate random strings. (copied from
internet with little mod)
#!/usr/bin/env python
import sys
import random
import string
def id_generator(size=6, chars=string.ascii_uppercase + string.digits):
return ''.join(random.choice(chars) for _ in range(size))
line=int(sys.argv[1])
for x in range(1,line):
print(id_generator())
Step 2: generate test data and put into home folder:
./random_string.py 1000 | hdfs dfs -p... 阅读全帖 |
|
w*******y
发帖数: 60932 | 27 Cosco 5-Piece Dining Set ( 4 Steel Frame Chairs and 1 Steel Frame Frosted
Glass Top Table) $59 at walmart:
http://www.walmart.com/ip/Cosco-5-Piece-Dining-Set/11018301
The Cosco 5-Piece Dining Set features a modern, contemporary design. It's
the perfect solution for your casual dining area or breakfast nook, and the
seat and back are constructed from durable polypropylen e.
The Cosco 5-Piece Dining Set includes a steel frame table and 4 chairs.
Cosco 5-Piece Dining Set:
Steel frame table and 4 c... 阅读全帖 |
|
|
w*******y
发帖数: 60932 | 29 Link:
http://www.lowes.com/pd_54545-16878-61404_0__?productId=3099919&Ntt=task force&pl=1¤tURL=/pl__0__s?Ntt=task+force&page=5
Sweeten the deal by buying 2 and using the Facebook 10 off 25 coupon to
bring price down to $10 each. Coupon codes can be found by searching this
forum. These tables normally list for $30. This table seems to be the
exact same table as the Black and Decker Workmate 125 that lists for even
higher.
Folks there are some poor reviews for this product but consider ho... 阅读全帖 |
|
w*******y
发帖数: 60932 | 30 Last night at Target in the Nashville, TN area they had some Sportcraft 4
Piece Table Tennis sets on clearance. It is the X-3000 I believe, and it may
have been left over from an $88 BF deal that Target ran. They had a few of
them at my Target.
The set showed a regular price of around $130 I believe. I don't know if
this national, but good luck if you are interested. This is Target B&M
clearance only, so the below Wal-Mart link is only to show the table and
details.
Link:
http://www.walmart.com... 阅读全帖 |
|
r*******e
发帖数: 69 | 31 【 以下文字转载自 Boston 讨论区 】
发信人: riverwave (江上烟波), 信区: Boston
标 题: Protest against Jimmy Kimmel Kid's Table Government Shutdown Show on
ABC Network
发信站: BBS 未名空间站 (Mon Oct 28 11:56:54 2013, 美东)
Protest against Jimmy Kimmel Kid's Table Government Shutdown Show on ABC
Network
Location: THE NEW ENGLAND HOLOCAUST MEMORIAL （ http://www.nehm.org/ ）
Time : Nov 2nd(Saturday), 11am -- 1pm
(Rain date : Nov 3rd, 11am – 1pm)
Why:
Jimmy Kimmel and the ABC network sent a very clear bad message that it was "
inter... 阅读全帖 |
|
发帖数: 1 | 32 雁过 发于 2020-01-29 05:12, 论坛:
标题: 细思极恐，排华2.0节奏？If You’re Not at the Table, You’re on the
Menu
最近所有被抓的各种中美大牛至少都跟中国千丝万缕的关系。
细思极恐，排华2.0节奏？If You’re Not at the Table, You’re on the Menu
这样的大牛都拉出来批斗了，估计这以后中国大陆来的孩子们想在美国搞高科技，发考
题，必然比之前要难了。
再仔细想想这几年民主党坚持不懈一直在背后推的国别细分，没有阴谋，我都不相信。
国别细分一旦成功，估计abc们不管几代也会非常辛苦，受到牵连。
不理睬政治的，将来政治肯定会来照顾你的子子孙孙。If You’re Not at the Table,
You’re on the Menu |
|
t*****m
发帖数: 15 | 33 二手交易风险自负！请自行验证是否合法和一手卡！:
我想卖的物品:
1 large working platform table
单张面值:
可接受价格(必须明码标价！):
1 large working platform table($50):2 stainless steel saw horse: each $20,
woodern table $20
物品新旧要求:
邮寄方式要求:
买卖双方谁承担邮寄损失(Required if not code only):
付款方式说明:
其他补充说明:
广告的有效期:
物品来源(Required for All Cards!):
我的联系方式:
T*****[email protected]
Warranty期限:
能否证明是合法的一手卡?(Required for All Cards!):
state and zip: |
|
|
m******i
发帖数: 29 | 35 Queen Size Bed - in perfect new condition $80
Queen Size mattress - $80
Take the bed and mattress set $150 together
Glass top Coffee table - in perfect new condition -- $70
Glass top dinner table for 4 --- $50, chairs to go $10 each， take the set
for $80
Furniture is in Forest Hills, Queen, NY 11375.
See pictures, pickup only, call 9178876727 |
|
n*******j
发帖数: 11 | 36 Dining/Coffee table Sale. Very good condition. All less than 3 years old.
Dining table with 4 chairs: $100
Coffee table: $100
Firm mattress with Box: $100
Wiindows air concidtioner LG: $50
Portable air concidtioner: $50 |
|
y****i
发帖数: 72 | 37 家里有1个Sofa Table($100)， 1个coffee table($100)，2个end tables($70each)转
让。4个桌子一起拿$300. |
|
b******h
发帖数: 2732 | 38 在文章里引用了别人发表的文章当中的一个table，除了给出reference之外，还要做些
别的什么？需要ask for permission么？那个table不是数据，就是描述性的，类似这
个现象大体分为三类etc那种table。 |
|
t*****m
发帖数: 15 | 39 Book:
English Version:
Principles of Corporate Finance(8th edition) (English content with English/
Chinese cover): $10
The hand book of Fixed Income Securities(6th edition)(English content with
English/Chinese cover):$10
Options, Futures and Other Derivatives(5th edition)(English content with
English/Chinese cover):$8
Chiniese Version:
Real Estate Financing and Investments（房地产投资与融资）-(11th edition) (in
Chinese):$5
The Second World War-Winston S. Churchill (第二次世界大战 丘吉尔)(6 books;
Chinese) $10
Furni... 阅读全帖 |
|
t*****m
发帖数: 15 | 40 二手交易风险自负！请自行验证是否合法和一手卡！:
我想卖的物品:
1 large working platform table
单张面值:
可接受价格(必须明码标价！):
1 large working platform table($50):2 stainless steel saw horse: each $20,
woodern table $20
物品新旧要求:
邮寄方式要求:
买卖双方谁承担邮寄损失(Required if not code only):
付款方式说明:
其他补充说明:
广告的有效期:
物品来源(Required for All Cards!):
我的联系方式:
T*****[email protected]
Warranty期限:
能否证明是合法的一手卡?(Required for All Cards!):
state and zip: |
|
|
m******i
发帖数: 29 | 42 Queen Size Bed - in perfect new condition $80
Queen Size mattress - $80
Take the bed and mattress set $150 together
Glass top Coffee table - in perfect new condition -- $70
Glass top dinner table for 4 --- $50, chairs to go $10 each， take the set
for $80
Furniture is in Forest Hills, Queen, NY 11375.
See pictures, pickup only, call 9178876727 |
|
n*******j
发帖数: 11 | 43 Dining/Coffee table Sale. Very good condition. All less than 3 years old.
Dining table with 4 chairs: $100
Coffee table: $100
Firm mattress with Box: $100
Wiindows air concidtioner LG: $50
Portable air concidtioner: $50 |
|
r******2
发帖数: 67 | 44 Moving from big house to an apartment building in Down town. We have 3 sets
of bedroom and living room furniture for sale. New, luxious and good
condition.
Bedroom Furniture for Sale:
1. Asking $1000. Yellow, 3-5 year old. Queens size bed with two good
mattresses, 2 night tables, 1 dressing, 1 closet, long glass table. Mint
condition, good for every room.
2. Asking $1000. Dark brown, twin size bed, 2 mattresses, 2 night table, 1
dressing, good condition. Good for apartment.
3. Asking $1500 White |
|
b*********n
发帖数: 464 | 45 写过几年程序，从未用过hash table, technical电面之前两次提到hash table. c/c++
有标准的hash table实现吗？感觉hash function得自己选啊 |
|
h****p
发帖数: 87 | 46 研究下KMP算法，看到wiki上的解释有一点不是很理解 请大牛帮忙解释解释
算table如下：
algorithm kmp_table:
input:
an array of characters, W (the word to be analyzed)
an array of integers, T (the table to be filled)
output:
nothing (but during operation, it populates the table)
define variables:
an integer, pos ← 2 (the current position we are computing in T)
an integer, cnd ← 0 (the zero-based index in W of the next
character of the current candidate substring)
(the first few v... 阅读全帖 |
|
l******9
发帖数: 579 | 47 【 以下文字转载自 Database 讨论区 】
发信人: light009 (light009), 信区: Database
标 题: SQL find distinct values in large table
发信站: BBS 未名空间站 (Wed May 21 17:20:16 2014, 美东)
I have a very large table with 1 billion rows and 12 columns, which are int,
double, varchar. I need to know the distinct values for each volume.
the table has columns :
id id_1 id_2 id_3 id_4 id_5 id_6 id_7 id_8 id_9 id_10 id_11
SELECT COUNT(distinct a.id) as num_dist_id
FROM my_large_table as a
SELECT distinct a.id
FR... 阅读全帖 |
|
l******9
发帖数: 579 | 48 On SQL server 2008, I need to get a new table by selecting two columns from
two different tables.
address (from another_table) id_num (from a cte created by me)
city_1 65
city_1 36
city_2 65
city_2 36
city_3 65
city_3 36
Suppose that id_num has only 65 and 36 two values. The cte has no column of
"address". the another_table has no column of id... 阅读全帖 |
|
l********e
发帖数: 103 | 49 面试时候
被问到 写个 多线程的hash table
hash table我用linked list解决collision 问题
加lock的时候 我说 要用read write lock
hash table insert 时候用write lock
get的时候用read lock
然后 面试官跟我说
get的时候 不用加任何lock
大不了 get的值是旧的
（我当时 没说话 心想 只要 让我过 你说什么都好）
不过 我不明白为什么get不用加任何lock
如果 一个现在正在更改 一个值 改着一半的时候
正好另一个线程过来读 这时候 岂不是 读出来的值 一般旧一半新
请问各位大侠 我哪里对多线程理解错了？
请指点
谢谢 |
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b********3
发帖数: 994 | 50 TABLE FUNDING 是指的investor直接出钱funding，不通过lender这一步。举个例子，
你的broker把你的loan介绍给了一个lender，lender可以选择一个investor，say
Chase。 Lender可以选择自己放钱，然后把loan卖给chase，或者是直接到chase申请
table funding。一般来说，这个费用不应该找borrower收的。Fast closing跟table
funding没有任何关系。不过总体来说，你800栏里面的费用还比较fair |
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