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What's the difference between TRUNCATE and DELETE in SQL
...cle
If you use the REUSE STORAGE clause then the data segments are not de-allocated, which can be marginally more efficient if the table is to be reloaded with data. The high water mark is reset.
Row scope
Delete can be used to remove all rows or only a subset of rows. Truncate removes all rows...
莱昂氏unix源代码分析 PDF - 文档下载 - 清泛网 - 专注C/C++及内核技术
... 初始化、进程初始化
第5章 两个文件 241
5.1 文件malloc.c 241
5.1.1 列表维护规则 241
5.1.2 malloc(2528) 242
5.1.3 mfree(2556) 243
5.1.4 结论 244
5.2 文件prf.c 244
5.2.1 printf(2340) 244
5.2.2 printn(2369) 245
5.2.3 putchar(2386) 246
5.2.4 p...
iOS: Access app-info.plist variables in code
... ofType: @"plist"];
NSMutableDictionary *dictplist =[[NSMutableDictionary alloc] initWithContentsOfFile:path];
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Performance of Java matrix math libraries? [closed]
...o use "raw" MOV instructions as you'd expect; it makes decisions on how to allocate variables to registers when it can; it re-orders instructions to take advantage of processor architecture... A possible exception is that as I mentioned, Hotspot will only perform one operation per SSE instruction; i...
Why use String.Format? [duplicate]
...the exact size of the destination string is known ahead of time and can be allocated immediately and each character copied only once.
– csauve
Jan 12 '11 at 17:44
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Why “decimal” is not a valid attribute parameter type?
...I suppose it comes under the 'array of primitives' category but it is heap allocated (reference type)...
– Steztric
Nov 11 '16 at 8:29
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Which cryptographic hash function should I choose?
... specifically for passwords, or for challenge-response auth, or for access tokens, or just to index a bunch of strings/files. Performance, on the other hand, is a concern for the OP...
– Seva Alekseyev
May 23 '19 at 17:33
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SQL select join: is it possible to prefix all columns as 'prefix.*'?
...result set for a list of columns in a scripting language such as Python or PHP.
SELECT '' as table1_dummy, table1.*, '' as table2_dummy, table2.*, '' as table3_dummy, table3.* FROM table1
JOIN table2 ON table2.table1id = table1.id
JOIN table3 ON table3.table1id = table1.id
I realize this doesn't ...
Java EE web development, where do I start and what skills do I need? [closed]
..., css, etc) just like a web server does. It is comparable to Apache with a php module.
– Nemi
Dec 24 '09 at 16:16
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What is the difference between pluck and collect in Rails?
... Because it will retrieve all the columns from user table in the database, allocates the memory for each attributes (including the attributes which you will never use)
NOTE: pluck does not return ActiveRecord_Relation of the user
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