[MonetDB-users] Bulk-importing boolean columns

Stefan de Konink stefan at konink.de
Wed Oct 19 10:44:10 CEST 2011


On Wed, 19 Oct 2011, Stefan Manegold wrote:

> ps: In MonetDB, we try to stick to SQL standards, and though I didn't check,
>    I don't think SQL specifies single letters "t" and "f" as keywords
>    representing boolean values TRUE and FALSE.

<truth value> ::=
       TRUE
     | FALSE
     | UNKNOWN

I do wonder if that same SQL92 dictates the use of UNKNOWN keyword why 
NULL is the only only tri-boolean value accepted then.

sql>create table bools (test boolean);
operation successful (77.133ms)
sql>insert into bools values (unknown);
SELECT: identifier 'unknown' unknown
sql>insert into bools values (null);
1 affected row (36.447ms)


Anyway... this hole deserialisation thing with respect to copy into. 
Wouldn't it be wise to be able to cast anything 'remotely' parsible into a 
value to be converted. That said for booleans also accept 0/1 so 
conversations from MSSQL are also directly possible? It is not that 
MonetDB behaves like SQLite3 when it is processing, but it would be very 
nice to reduce the time in 'exact format conversions' for an operation 
that should be done once, were after, it will be always correct 
because MonetDB does follow specifications.


Stefan




More information about the users-list mailing list