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Is it possible to Pivot data using LINQ?
... 3).Sum(c => c.Qty)
});
GroupBy in Linq does not work the same as SQL. In SQL, you get the key and aggregates (row/column shape). In Linq, you get the key and any elements as children of the key (hierarchical shape). To pivot, you must project the hierarchy back into a row/column form of...
Do I need to create indexes on foreign keys on Oracle?
...t creates also an index... i.e. Jet Engine (MSAccess files, Firebird and MySQL)
– bubi
Apr 23 '15 at 15:19
17
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What scalability problems have you encountered using a NoSQL data store? [closed]
NoSQL refers to non-relational data stores that break with the history of relational databases and ACID guarantees. Popular open source NoSQL data stores include:
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Cause of a process being a deadlock victim
...5 to 10 minutes. I am currently not using NOLOCK as a hint to the MS SQL database engine. At the same time we have another process doing updates and inserts into the same database and same tables. The first process has started, recently to end prematurely with a message
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What are named pipes?
...ften, a commonly used standard default exists (much like port 80 for HTTP, SQL server uses port 1433 in TCP/IP; \\.\pipe\sql\query for a named pipe).
By setting up additional named pipes, you can have multiple DB servers running, each with its own request listeners.
The advantage of named pipes is...
How to thoroughly purge and reinstall postgresql on ubuntu? [closed]
Somehow I've managed to completely bugger the install of postgresql on Ubuntu karmic. I want to start over from scratch, but when I "purge" the package with apt-get it still leaves traces behind such that the reinstall configuration doesn't run properly.
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Copying data from one SQLite database to another
I have 2 SQLite databases with common data but with different purposes and I wanted to avoid reinserting data, so I was wondering if it was possible to copy a whole table from one database to another?
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How to list only the file names that changed between two commits?
...ite/rex/RexSimplify.java | 50 +++++++++++++++++-----
.../apache/calcite/sql/fun/SqlTrimFunction.java | 2 +-
.../apache/calcite/sql2rel/SqlToRelConverter.java | 16 +++++++
.../org/apache/calcite/util/SaffronProperties.java | 19 ++++----
.../org/apache/calcite/test/RexProgramTest.java | ...
获取文件系统映像及恢复删除的数据（FAT文件系统格式描述） - C/C++ - 清泛...
...
17-18
根目录的文件数目，在 FAT32格式中它的值是 NULL ，无实际意义。
是
19-20
文件系统的扇区数。如果这个值超过了 65535 ，则其值是 NULL，第 32 到35 字节存储了文件系统的大小。
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【内核源码】linux UDP实现 - 操作系统(内核) - 清泛网 - 专注C/C++及内核技术
...址的情况下，有可能导致单个链表的上有很多socket，导致查询慢
添加第二个hash表，使用地址和端口作为key， 来应对上述情况。 查询的时候只用查两个hash链表中较短的那个。
udp sencondary hash
connect()
sys_connect()->inet_dgram_connect...