[ZODB-Dev] RelStorage - zodbconvert script and the --clear flag

[Shane Hathaway]

On 08/31/2011 05:11 PM, Darryl Dixon - Winterhouse Consulting wrote:
>> Just had a quick query from my friendly local DBA; he wanted to know why
>> --clear was using DELETE rather than TRUNCATE; his comments were along the
>> lines of:
>> * TRUNCATE creates no UNDO
>> * TRUNCATE cleans out the indexes nicer
>>
>> Is there any real downside or gotcha I should be aware of to following
>> this suggestion in this instance?
>
> To be clear:
>
> This is RelStorage 1.5.0 running against Oracle RAC 10g.
>
> I tried changing the line in question (relstorage/adapters/schema.py line
> 895) to "TRUNCATE TABLE %s" % table, and the following error is generated:
> ORA-02266: unique/primary keys in table referenced by enabled foreign keys
>
> So I guess without a bunch of work it will not be possible.

Is clearing the database a common operation that should be tuned for 
performance?  That part of the code is optimized for safety and 
readability, not performance.

Shane