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Re: Feature Request - Working auto_inc rement on BlackHole Engine
>>>>> "Gordan" == Gordan Bobic <gordan@xxxxxxxxxx> writes:
Gordan> On 05/15/2013 09:24 PM, Roberto Spadim wrote:
>> hum, maybe a 'global variable' + a 'counter' function could do the job?
>> select add_and_return(@global_var,1)
>> could return old global_var value +1, and set the global_var to +1
>> just a idea.. like GET_LOCK(str,timeout) do, but without timeout
Gordan> How would the function avoid the race condition?
By using atomic auto increments supported by the cpu.
If you make this a two fold number:
32_bit_timestamp << 32 + auto_increment
Then this would even be safe in regards for server crashes.
Gordan> Is it actually possible to have user-defined global variables?
With a plugin, yes.