Re: SQL Date field storage versus PF DDS storage

[Mark Waterbury <mark.s.waterbury@xxxxxxxxxxxxx>]

 Hi, Vern,
It has always been documented that Db2i uses 8 bytes internally for a Timestamp, and 4 bytes for a date.  And, the "database" has always "materialized" those date/time fields as some number of character positions, for consumption by HLLs, etc.
IIRC, the "binary" representation for a date in that storage is actually just the rightmost 4 bits of each digit of the zoned decimal representation... (sort of like packed decimal without the sign.)

Just saying ...
Mark 


    On Monday, March 25, 2019, 12:02:14 PM EDT, Vernon Hamberg <vhamberg@xxxxxxxxxxxxxxx> wrote:  
 
 To add to confusion or clarity - not sure - the SQL catalog SYSCOLUMNS 
has the actual storage length -

select * from syscolumns where table_name = 'your-table-with-date-column';

You'll see something different.

I though I've seen this information gathered together somewhere - maybe 
DBU - maybe one of the IBM i services.

HTH
Vern

On 3/25/2019 10:12 AM, Mark Waterbury wrote:
>   Paul,
> Date fields in Db2i have always occupied 4 bytes internally. When the date field is materialized by the database, it is converted from its internal binary form to and appears as 10 decimal character (zoned decimal) positions.
> This is true whether a database file is defined by DDS using e.g. CRTPF or a table is defined via SQL DDL.
> Hope that helps,
> Mark S. Waterbury
>
>       On Monday, March 25, 2019, 11:08:44 AM EDT, Therrien, Paul via MIDRANGE-L <midrange-l@xxxxxxxxxxxxxxxxxx> wrote:
>   
>   This may not be too important, but seems to be an anachronism.
>
> I have a table that is built with SQL DDL and one of the fields is a date field defined as:
> PIPRJSDT      DATE      NOT NULL DEFAULT CURRENT_DATE;
>
> When I Interrogate the file with DSPFFD I see the date field as taking 10 positions:
>
>                         Data        Field      Buffer  Buffer          Field      Column
>   Field          Type      Length  Length  Position        Usage    Heading
>   PIPRJSDT  DATE          10      10            63                  Both      Project
>                                                                                                                   Ship
>                                                                                                                   Date
>     Field text  . . . . . . . . . . . . . . . :  Projected ship date
>     Date Format . . . . . . . . . . . . . . . :  *ISO
>     Default value . . . . . . . . . . . . . . :
>         CURRENT_DATE
>     Coded Character Set Identifier  . . . . . :    37
>
> When I interrogate the field using the SYSCOLUMNS I see this:
> Column_Name Data Type    Length  Storage
> PIPRJSDT        DATE                  4                4
>
> I suppose this is expected, but I wasn't expecting this.
>
> I found this while trying to generate a file layout using SYSCOLUMNS to excel and was trying to create a file layout listing column starting positions.
>
>
> Paul
>
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