If you're on a Unix-like platform (Mac OS X, Linux, etc), you could try running file myfile.db to see if that can figure out what type of file it is. The file utility will inspect the beginning of the file, looking for any clues like magic numbers, headers, and so on to determine the type of the file.

2013年10月3日 · 用分贝表示场量比值时，就会写作： L_{dB}=20log_{10}(A_{1}/A_{0}) 。 二、使用dB这个单位的原因. 首先说说为什么在表达声音响亮强度时，常采用dB这个单位。这主要是因为：人们感官所感觉到声音响度的变化，是与有关量值在变化前后的比值的对数成正比的。

I don't think there is a way to tell which program to use from just the .db extension. It could even be an encrypted database which can't be opened. You can MS Access, or a sqlite manager. Edit: Try to rename the file to .txt and open it with a text editor. The first couple of words in the file could tell you the DB Type.

2020年7月12日 · The .db file extension is used by Oracle, Paradox and XoftSpySE databases. As Christian noted usually extensions aren't that important in the grand scheme of things and programs can open files with different extensions.

+3 dB = 2x 功率 +6 dB = 4x 功率. dB与dBm的区别总结如下： dB定义为任意两个给定点之间的功率或信号强度之差，而dBm则定义为功率的绝对值或强度，用于确定特定点的信号强度。 与dB不同，dBm是绝对测量单位。dB代表一个相对数字，表示信号强度的增加或减少。

2013年6月30日 · The DB statement initializes memory with one or more byte values. label is a symbol that is assigned the current memory address. expression is a byte value that is stored in memory. Each expression may be a symbol, a string, or an expression.

2022年12月19日 · DB - Define Byte. 8 bits; DW - Define Word. Generally 2 bytes on a typical x86 32-bit system; DD - Define double word. Generally 4 bytes on a typical x86 32-bit system; From x86 assembly tutorial, The pop instruction removes the 4-byte data element from the top of the hardware-supported stack into the specified operand (i.e. register or memory ...

2012年6月8日 · Once you have that user in your database, you can give it any rights you want, e.g. you could assign it the db_datareader database role to read all tables. USE (your database) EXEC sp_addrolemember 'db_datareader', '(your user name)'

2009年1月13日 · Shrink db (right-click db, choose all tasks > shrink db -> set to 10% free space) Verify that the space has been reclaimed, if not you might have to do a full backup; If that doesn't work (or you get a message saying "log file is full" when you try to switch recovery modes), try this: Backup; Kill all connections to the db

2012年3月21日 · Jorg is correct that dB SPL is a relative measurement. All decibel measurements are. But you've implied a reference of 0 dB SPL, or 20 micropascals, scientifically agreed to be the most quiet sound a human ear can detect (though, understandably, what a person can actually hear is very difficult to determine).