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MongoDB vs. Cassandra [closed]
...sandra: they are not using Cassandra for persisting tweets, they use still MySQL here (engineering.twitter.com/2010/07/cassandra-at-twitter-today.html). Ok, but I can imagine that they still store lots of data for other purposes in Cassandra.
– H6.
Jan 13 '12 a...
How do I check if a SQL Server text column is empty?
...
Actually, you just have to use the LIKE operator.
SELECT * FROM mytable WHERE mytextfield LIKE ''
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Where are my postgres *.conf files?
...alives_idle = 0 # TCP_KEEPIDLE, in seconds;
# 0 selects the system default
#tcp_keepalives_interval = 0 # TCP_KEEPINTVL, in seconds;
# 0 selects the system default
#tcp_keepalives_count = 0 # TCP_KEEPCNT;
# 0 selects the...
Python 3 ImportError: No module named 'ConfigParser'
I am trying to pip install the MySQL-python package, but I get an ImportError .
18 Answers
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领域驱动设计系列（五）:事件驱动之异步事件 - 更多技术 - 清泛网 - 专注C/...
...以。
另外，异步要处理的东西很多，比如处理完毕后，如何通知用户，还是让用户刷新？ 我个人建议，一般情况下都不要用异步，只有在真的需要的时候再用。
作者: 王德水
出处：http://deshui.wang
领域驱动设计 DDD 事件驱...
How can I temporarily disable a foreign key constraint in MySQL?
Is it possible to temporarily disable constraints in MySQL?
10 Answers
10
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Python SQL query string formatting
...qualified a somewhere between Option 2 and Option 4
Code Sample:
sql = ("SELECT field1, field2, field3, field4 "
"FROM table "
"WHERE condition1=1 "
"AND condition2=2;")
Works as well with f-strings:
fields = "field1, field2, field3, field4"
table = "table"
conditions = "co...
Avoid duplicates in INSERT INTO SELECT query in SQL Server
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Using NOT EXISTS:
INSERT INTO TABLE_2
(id, name)
SELECT t1.id,
t1.name
FROM TABLE_1 t1
WHERE NOT EXISTS(SELECT id
FROM TABLE_2 t2
WHERE t2.id = t1.id)
Using NOT IN:
INSERT INTO TABLE_2
(id, name)
SELECT t1.id,
t1....
Can't choose class as main class in IntelliJ
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Select the folder containing the package tree of these classes, right-click and choose "Mark Directory as -> Source Root"
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When should I use Kruskal as opposed to Prim (and vice versa)?
...c.
If you implement both Kruskal and Prim, in their optimal form : with a union find and a finbonacci heap respectively, then you will note how Kruskal is easy to implement compared to Prim.
Prim is harder with a fibonacci heap mainly because you have to maintain a book-keeping table to record the...