Re: sequence question
Hello Bp If you use the sequence for unique identifiers only, you do not need to worry about this. At most the numbers will go from 1234 to 11234 and continue from there. So what? Yechiel AdarMehish - Original Message - From: BigP To: Multiple recipients of list ORACLE-L Sent: Friday, June 14, 2002 3:23 AM Subject: sequence question Hi List , I want to create a sequence which will be used by some external process to generate some unique number . since this sequence will be used very frequently I would prefer to cache around 1 numbers . Am I going to loose some numbers ? what is SEQUENCE_CACHE_ENTRIES and how does it affect number or sequence cached ? Thanks , -Bp
Re: sequence question
Bigp Remember that when you issue sequence.nextval you are incrementing one value and eitheryour process function corrector not that number is used. But, the more important is that if your system crash or you issue an SHUTDOWN ABORT you will loose the sequence numbers cached. Also you can loose numbers after an Import / Export. Luck, Ramon - Original Message - From: BigP To: Multiple recipients of list ORACLE-L Sent: Thursday, June 13, 2002 8:23 PM Subject: sequence question Hi List , I want to create a sequence which will be used by some external process to generate some unique number . since this sequence will be used very frequently I would prefer to cache around 1 numbers . Am I going to loose some numbers ? what is SEQUENCE_CACHE_ENTRIES and how does it affect number or sequence cached ? Thanks , -Bp
RE: sequence question
what do you mean about losing numbers after an import/export? -Original Message-From: Ramon E. Estevez [mailto:[EMAIL PROTECTED]]Sent: Friday, June 14, 2002 10:44 AMTo: Multiple recipients of list ORACLE-LSubject: Re: sequence question Bigp Remember that when you issue sequence.nextval you are incrementing one value and eitheryour process function corrector not that number is used. But, the more important is that if your system crash or you issue an SHUTDOWN ABORT you will loose the sequence numbers cached. Also you can loose numbers after an Import / Export. Luck, Ramon - Original Message - From: BigP To: Multiple recipients of list ORACLE-L Sent: Thursday, June 13, 2002 8:23 PM Subject: sequence question Hi List , I want to create a sequence which will be used by some external process to generate some unique number . since this sequence will be used very frequently I would prefer to cache around 1 numbers . Am I going to loose some numbers ? what is SEQUENCE_CACHE_ENTRIES and how does it affect number or sequence cached ? Thanks , -Bp
Re: sequence question
Bill, When you do an export you have sequence numbers in cache. Ramon - Original Message - From: Magaliff, Bill To: Multiple recipients of list ORACLE-L Sent: Friday, June 14, 2002 10:53 AM Subject: RE: sequence question what do you mean about losing numbers after an import/export? -Original Message-From: Ramon E. Estevez [mailto:[EMAIL PROTECTED]]Sent: Friday, June 14, 2002 10:44 AMTo: Multiple recipients of list ORACLE-LSubject: Re: sequence question Bigp Remember that when you issue sequence.nextval you are incrementing one value and eitheryour process function corrector not that number is used. But, the more important is that if your system crash or you issue an SHUTDOWN ABORT you will loose the sequence numbers cached. Also you can loose numbers after an Import / Export. Luck, Ramon - Original Message - From: BigP To: Multiple recipients of list ORACLE-L Sent: Thursday, June 13, 2002 8:23 PM Subject: sequence question Hi List , I want to create a sequence which will be used by some external process to generate some unique number . since this sequence will be used very frequently I would prefer to cache around 1 numbers . Am I going to loose some numbers ? what is SEQUENCE_CACHE_ENTRIES and how does it affect number or sequence cached ? Thanks , -Bp
Re: sequence question
while going throgh oracle manuals I found saying number of sequence cached is governed by init parameter SEQUENCE_CACHE_ENTRIES . Does it mean that this value should be set = 'number of sequence I want to cache' ...and what happens if a sequence gets aged out from sequence pool . Am I going to loose numbers ? Did any of you guys tried caching high number such as 1 or 100 . Thanks , Bp - Original Message - From: Magaliff, Bill To: Multiple recipients of list ORACLE-L Sent: Friday, June 14, 2002 8:53 AM Subject: RE: sequence question what do you mean about losing numbers after an import/export? -Original Message-From: Ramon E. Estevez [mailto:[EMAIL PROTECTED]]Sent: Friday, June 14, 2002 10:44 AMTo: Multiple recipients of list ORACLE-LSubject: Re: sequence question Bigp Remember that when you issue sequence.nextval you are incrementing one value and eitheryour process function corrector not that number is used. But, the more important is that if your system crash or you issue an SHUTDOWN ABORT you will loose the sequence numbers cached. Also you can loose numbers after an Import / Export. Luck, Ramon - Original Message - From: BigP To: Multiple recipients of list ORACLE-L Sent: Thursday, June 13, 2002 8:23 PM Subject: sequence question Hi List , I want to create a sequence which will be used by some external process to generate some unique number . since this sequence will be used very frequently I would prefer to cache around 1 numbers . Am I going to loose some numbers ? what is SEQUENCE_CACHE_ENTRIES and how does it affect number or sequence cached ? Thanks , -Bp
Re: sequence question
Acording to the manuals SEQUENCE_CACHE_ENTRIES is an obsolete parameter for 8.1.7 Ramon - Original Message - From: BigP To: Multiple recipients of list ORACLE-L Sent: Friday, June 14, 2002 12:49 PM Subject: Re: sequence question while going throgh oracle manuals I found saying number of sequence cached is governed by init parameter SEQUENCE_CACHE_ENTRIES . Does it mean that this value should be set = 'number of sequence I want to cache' ...and what happens if a sequence gets aged out from sequence pool . Am I going to loose numbers ? Did any of you guys tried caching high number such as 1 or 100 . Thanks , Bp - Original Message - From: Magaliff, Bill To: Multiple recipients of list ORACLE-L Sent: Friday, June 14, 2002 8:53 AM Subject: RE: sequence question what do you mean about losing numbers after an import/export? -Original Message-From: Ramon E. Estevez [mailto:[EMAIL PROTECTED]]Sent: Friday, June 14, 2002 10:44 AMTo: Multiple recipients of list ORACLE-LSubject: Re: sequence question Bigp Remember that when you issue sequence.nextval you are incrementing one value and eitheryour process function corrector not that number is used. But, the more important is that if your system crash or you issue an SHUTDOWN ABORT you will loose the sequence numbers cached. Also you can loose numbers after an Import / Export. Luck, Ramon - Original Message - From: BigP To: Multiple recipients of list ORACLE-L Sent: Thursday, June 13, 2002 8:23 PM Subject: sequence question Hi List , I want to create a sequence which will be used by some external process to generate some unique number . since this sequence will be used very frequently I would prefer to cache around 1 numbers . Am I going to loose some numbers ? what is SEQUENCE_CACHE_ENTRIES and how does it affect number or sequence cached ? Thanks , -Bp
RE: sequence question
Short answer - yes you could loose some numbers. Have a look at http://www.ixora.com.au/scripts/library.htm and the unload_sequences.sql and keep_sequences.sql which mention that you can lose when: Shutdown abort is done the sequence gets aged out of the library cache The scripts suggest 2 ways to help avoid this. If its really critical to never skip a number then maybe you shouldn't cache the sequence. But then again, if its that critical maybe you shouldn't use a sequence - eg what if someone gets the sequence number and then does a rollback. It is my understanding from a simple test that you will now have a hole / gap in the sequence numbers. So, does a gap REALLY matter (ie can you never have a gap) or is it just that you need to avoid gaps where possible. HTH, Bruce Reardon -Original Message- Sent: Friday, 14 June 2002 11:23 Hi List , I want to create a sequence which will be used by some external process to generate some unique number . since this sequence will be used very frequently I would prefer to cache around 1 numbers . Am I going to loose some numbers ? what is SEQUENCE_CACHE_ENTRIES and how does it affect number or sequence cached ? Thanks , -Bp -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Reardon, Bruce (CALBBAY) INET: [EMAIL PROTECTED] Fat City Network Services-- (858) 538-5051 FAX: (858) 538-5051 San Diego, California-- Public Internet access / Mailing Lists To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
