RE: Primary Key generation - size limit
RE: Primary Key generation - size limit
- Subject: RE: Primary Key generation - size limit
- From: Chuck Hill <email@hidden>
- Date: Sat, 24 Apr 2004 09:42:39 -0700
It depends more on the database than the adaptor/plugin. You can always
drop and recreate the EO_PK_TABLE. Hmmm, assuming the plugin can handle
the change. If not you might need to make some small alterations to the
plugin. Other databases (FrontBase, Oracle, OpenBase sort of) have their
own PK generators so a lot depends on what range they supply before rolling
over. If memory serves, it was rather huge.
Chuck
At 01:08 PM 24/04/2004 +0200, Ruenagel, Frank wrote:
>Hi Chuck,
>
>Isn't this really adaptor dependent? With MS_SQl_Server
>by default the EO_PK_Table-Method for creating the PKs is unsed.
>And int this table the data-type of PK is 'int'. Not 'bigint', simple
>int (4 Bytes). Also I have heard that this datatype is hardcoded
>in the MSSQL-adaptor's java-code for generating the PK.... :(
>
>Please correct me if I have misunderstood something.
>Thank you!
>
>Frank
>
>
>> -----Original Message-----
>> From: Chuck Hill [mailto:email@hidden]
>> Sent: Friday, April 23, 2004 6:52 PM
>> To: Jacky Gagnon
>> Cc: email@hidden
>> Subject: Re: Primary Key generation - size limit
>>
>>
>> It just goes. It is a matter of choosing the appropriate
>> Java type to
>> hold the size of data that the database stores. You will
>> want to look
>> at your DB docs and see what will fit in the column type you
>> are using.
>>
>>
>> On Apr 23, 2004, at 9:44 AM, Jacky Gagnon wrote:
>>
>> > Hi Chuck
>> >
>> > Do I need to use databaseContextNewPrimaryKey if i use a long?
>> >
>> > Because in documentation, Apple talk about using a simple
>> Integer for
>> > pk Generation by WO...
>> >
>> > Thanks
>> >
>> > Jacky
>> >
>> >
>> > Le 04-04-23, ` 12:27, Chuck Hill a icrit :
>> >
>> >> java.lang.Long valueType l
>> >>
>> >>
>> >>
>> >>
>> >> On Apr 23, 2004, at 8:48 AM, Jacky Gagnon wrote:
>> >>
>> >>> Hi,
>> >>>
>> >>> By default WebObjects use Integer for storing PK.
>> Integer have a max
>> >>> value of 231-1. In other word the limit is not infinite,
>> especially
>> >>> when record are deleted regularly from a table (gap are created
>> >>> because
>> >>> some primary key value are lost, not reused by WO).
>> >>>
>> >>> Whats the best stategy in this case, if I don't want to reach this
>> >>> limit?
>> >>>
>> >>> -Using a bigger number (long) or binary keys (24 bytes).
>> >>> -Trying reusing objects (vs deleting these objects) to
>> avoid gaps in
>> >>> keys generation.
>> >>> -Trying to avoid gaps into pk generation algorithm.
>> >>>
>> >>> If you can point me to some documentation or case studies about
>> >>> strategies in pk generation...
>> >>>
>> >>>
>> >>> Thanks!
>> >>>
>> >>> Jacky :-)
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>
--
Chuck Hill email@hidden
Global Village Consulting Inc. http://www.global-village.net
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