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“open/close” SqlConnection or keep open?
...d Dec 14 '10 at 13:02
Adriaan StanderAdriaan Stander
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What's the difference between findAndModify and update in MongoDB?
I'm a little bit confused by the findAndModify method in MongoDB. What's the advantage of it over the update method? For me, it seems that it just returns the item first and then updates it. But why do I need to return the item first? I read the MongoDB: the definitive guide and it says that i...
What happens to global and static variables in a shared library when it is dynamically linked?
I'm trying to understand what happens when modules with globals and static variables are dynamically linked to an application.
By modules, I mean each project in a solution (I work a lot with visual studio!). These modules are either built into *.lib or *.dll or the *.exe itself.
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Restoring MySQL database from physical files
... this is true only for MyISAM tables. InnoDB stores its tables and indexes in a single tablespace *, which by default consist of the 3 files ibdata1, ib_logfile0, and ib_logfile1. for restoring a database, you would also need those files. * per-table tablespaces are possible, but not de...
How do I run Redis on Windows?
... port for Redis, but this repository has not been maintained for some time and implements an older version of Redis than the Microsoft port.
It should be noted that the official port is no longer maintained either, and Microsoft recommends yet another alternative for the latest Redis features. Howev...
unix - head AND tail of file
Say you have a txt file, what is the command to view the top 10 lines and bottom 10 lines of file simultaneously?
20 Answer...
Android error: Failed to install *.apk on device *: timeout
I'm getting this error from time to time and don't know what causing this:
When trying to run/debug an Android app on a real device (Galaxy Samsung S in my case) I'm getting the following error in the Console:
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Fastest way to count exact number of rows in a very large table?
...ECT COUNT(*) FROM TABLE_NAME will be slow when the table has lots of rows and lots of columns.
25 Answers
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MySQL: @variable vs. variable. What's the difference?
...are loosely typed variables that may be initialized somewhere in a session and keep their value until the session ends.
They are prepended with an @ sign, like this: @var
You can initialize this variable with a SET statement or inside a query:
SET @var = 1
SELECT @var2 := 2
When you develop a stor...
What's the difference between a catalog and a schema in a relational database?
... other things--all of the various schemas (external, conceptual, internal) and all of the corresponding mappings (external/conceptual, conceptual/internal) are kept.
In other words, the catalog contains detailed information (sometimes called descriptor information or metadata) regarding the va...