RE: global sequence as unique identifier across multiple databases
- From: "Dunbar, Norman" <norman.dunbar@xxxxxxxxxxxxxxxxxxxxxxxxx>
- To: <jkstill@xxxxxxxxx>
- Date: Wed, 1 Aug 2007 09:11:13 +0100
Jared wrote :
>> Anyone here ever do the math to determine how long it will take
>> to max out a sequence?
>> With a maximum value of 9,999,999,999,999,999,999,999,999,999 for a
single
>> sequence, how long will it take a site consuming 1000 sequences per
second
>> to exhaust the sequence?
9...9/1000/60/60/24/365.25/100 = 316880878140290 millennia.
>>
>> Or at 1,000,000 sequnces per second?
>>
9...9/1000000/60/60/24/365.25/100 = 316880878140.29 millennia.
Couldn't resist ...
Anyway, the *real* problem is not usually 'running out of allotted
lifespan' before the sequence expires, but more likely to be that the
column in the table is defined as NUMBER(7) or similar but the feeding
sequence is defined with no max value - how many times have I seen this
when health checking a database I wonder?
Cheers,
Norman.
Contract Oracle DBA
Internal : 7 28 2051
External : 0113 231 2051
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