[Monetdb-developers] Suggestion to ditch SHA-1, and embrace SHA-2

Stefan de Konink stefan at konink.de
Sun May 17 20:26:07 CEST 2009


Roberto Cornacchia wrote:
> 2. The restore is almost unusable for large databases, as it is
> extremely slow. I suspect the main reasons being:
> - COPY INTO .. FROM STDIN (used in the dump) is much much slower than
> copying from a file, regardless of whether the number or record to copy
> is given or not.

This is my conclusion as well.

> - Column constraints, as primary key, not null, etc, are issued upon
> table creation, before the COPY INTO, rather than being postponed with
> an ALTER TABLE after the copy (FOREIGN KEYS are instead postponed to the
> end of the script).

I have interesting results; it seems to be actually ~5% faster to 
*insert* with a primary key, opposed to postpone it (!) This even 
excludes the time to enforce the primary key afterwards.

I have verified in different runs that it is not related to the 'NOT 
NULL' constraints. So this is a pretty surprising results.


The data was highly structural and had a multicolumn primary key.


Stefan





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