Oracle sequences in Tickets table being skipped

RT Users
1

Hi all,
We are using RT 3.4.4, fastcgi and Oracle in our production environment.
The problem that we are facing right now is that ticket creation is
created in skipped sequences. I checked up the TICKETS.SEQUENCE script
and found that there is a cache option=20 being provided. I did check up
on the internet and found this website:
Sequences with "cache" option can skip numbers , which says that :
Applications which use Oracle sequences which have the CACHE option
enabled will often ‘skip’ values.

DROP SEQUENCE RT.TICKETS_SEQ;

CREATE SEQUENCE RT.TICKETS_SEQ
START WITH 6051
MAXVALUE 999999999999999999999999999
MINVALUE 1
NOCYCLE
CACHE 20
NOORDER;

Did anyone have this problem of skipping oracle sequences? If yes, how
did you solve it? It would be really helpful if some one could give me
tips how to go about this.

Thanks,
Ahalya Nathan
Senior Programmer / Analyst
Information Technology, Metropolitan Utilities District
(402) 504-7180 phone
(402) 504-5180 fax

2

At Monday 1/9/2006 12:52 PM, Nathan, Ahalya wrote:

Hi all,

We are using RT 3.4.4, fastcgi and Oracle in our production environment.
The problem that we are facing right now is that ticket creation is
created in skipped sequences. I checked up the TICKETS.SEQUENCE script and
found that there is a cache option=20 being provided. I did check up on
the internet and found this website:
Sequences with "cache" option can skip numbers , which says that :

Applications which use Oracle sequences which have the CACHE option
enabled will often ‘skip’ values.

Did anyone have this problem of skipping oracle sequences? If yes, how did
you solve it? It would be really helpful if some one could give me tips
how to go about this.

The article you point to seems to do a pretty good job explaining why this
happens and how to minimize the effect. What was it you needed to know that
the article didn’t cover? Also, I’m wondering why this is a problem?

Steve

3

At Monday 1/9/2006 12:52 PM, Nathan, Ahalya wrote:

Hi all,

We are using RT 3.4.4, fastcgi and Oracle in our production environment.
The problem that we are facing right now is that ticket creation is
created in skipped sequences. I checked up the TICKETS.SEQUENCE script and
found that there is a cache option=20 being provided. I did check up on
the internet and found this website:
Sequences with "cache" option can skip numbers , which says that :

Applications which use Oracle sequences which have the CACHE option
enabled will often ‘skip’ values.

Did anyone have this problem of skipping oracle sequences? If yes, how did
you solve it? It would be really helpful if some one could give me tips
how to go about this.

The article you point to seems to do a pretty good job explaining why this
happens and how to minimize the effect. What was it you needed to know that
the article didn’t cover? Also, I’m wondering why this is a problem?

Steve

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Think long and hard about not using an Oracle Sequence. You really must
ask yourself if the gaps are a real problem.

4

This hasn’t caused a problem so far, because we are not missing any
tickets. When many tickets were created and some go out of sequence,
users got a little confused as to why the creation of tickets was not
happening in sequence. I was wondering if there is any impact if I have
the NOCACHE option for the Ticket Sequences in RT. I couldn’t understand
why this is happening now because we had RT3.4.1(before we changed to RT
3.4.4) with the same Oracle database and then the tickets were always
created in sequence.

Ahalya Nathan
Senior Programmer / Analyst
Information Technology, Metropolitan Utilities District
(402) 504-7180 phone
(402) 504-5180 faxFrom: Stephen Turner [mailto:sturner@MIT.EDU]
Sent: Monday, January 09, 2006 12:07 PM
To: Nathan, Ahalya; rt-users@lists.bestpractical.com
Subject: Re: [rt-users] Oracle sequences in Tickets table being skipped

At Monday 1/9/2006 12:52 PM, Nathan, Ahalya wrote:

Hi all,

We are using RT 3.4.4, fastcgi and Oracle in our production
environment.
The problem that we are facing right now is that ticket creation is
created in skipped sequences. I checked up the TICKETS.SEQUENCE script
and
found that there is a cache option=20 being provided. I did check up on

the internet and found this website:
Sequences with "cache" option can skip numbers , which says that :

Applications which use Oracle sequences which have the CACHE option
enabled will often ‘skip’ values.

Did anyone have this problem of skipping oracle sequences? If yes, how
did
you solve it? It would be really helpful if some one could give me tips

how to go about this.

The article you point to seems to do a pretty good job explaining why
this
happens and how to minimize the effect. What was it you needed to know
that
the article didn’t cover? Also, I’m wondering why this is a problem?

Steve

5

Hi all,
We are using RT 3.4.4, fastcgi and Oracle in our production environment.
The problem that we are facing right now is that ticket creation is
created in skipped sequences. I checked up the TICKETS.SEQUENCE script
and found that there is a cache option=20 being provided. I did check up
on the internet and found this website:
Sequences with "cache" option can skip numbers , which says that :
Applications which use Oracle sequences which have the CACHE option
enabled will often ‘skip’ values.

DROP SEQUENCE RT.TICKETS_SEQ;

CREATE SEQUENCE RT.TICKETS_SEQ
START WITH 6051
MAXVALUE 999999999999999999999999999
MINVALUE 1
NOCYCLE
CACHE 20
NOORDER;

Did anyone have this problem of skipping oracle sequences? If yes, how
did you solve it? It would be really helpful if some one could give me
tips how to go about this.

Thanks,
Ahalya Nathan
Senior Programmer / Analyst
Information Technology, Metropolitan Utilities District
(402) 504-7180 phone
(402) 504-5180 fax

This also explains a bit about the “problem”.
http://asktom.oracle.com/pls/ask/f?p=4950:8:13106606684696238736::NO::F4950_P8_DISPLAYID,F4950_P8_CRITERIA:530735152441

6

Thanks a ton for the link. It helped.

Ahalya Nathan
Senior Programmer / Analyst
Information Technology, Metropolitan Utilities District
(402) 504-7180 phone
(402) 504-5180 faxFrom: Robert Blackwell [mailto:rdblackw@robertblackwell.com]
Sent: Monday, January 09, 2006 12:16 PM
To: Nathan, Ahalya
Cc: rt-users@lists.bestpractical.com
Subject: Re: [rt-users] Oracle sequences in Tickets table being skipped

Hi all,
We are using RT 3.4.4, fastcgi and Oracle in our production
environment.
The problem that we are facing right now is that ticket creation is
created in skipped sequences. I checked up the TICKETS.SEQUENCE script
and found that there is a cache option=20 being provided. I did check
up
on the internet and found this website:
Sequences with "cache" option can skip numbers , which says that :
Applications which use Oracle sequences which have the CACHE option
enabled will often ‘skip’ values.

DROP SEQUENCE RT.TICKETS_SEQ;

CREATE SEQUENCE RT.TICKETS_SEQ
START WITH 6051
MAXVALUE 999999999999999999999999999
MINVALUE 1
NOCYCLE
CACHE 20
NOORDER;

Did anyone have this problem of skipping oracle sequences? If yes, how
did you solve it? It would be really helpful if some one could give me
tips how to go about this.

Thanks,
Ahalya Nathan
Senior Programmer / Analyst
Information Technology, Metropolitan Utilities District
(402) 504-7180 phone
(402) 504-5180 fax

This also explains a bit about the “problem”.
http://asktom.oracle.com/pls/ask/f?p=4950:8:13106606684696238736::NO::F4
950_P8_DISPLAYID,F4950_P8_CRITERIA:530735152441