Am Freitag, 3. Dezember 2004 13:18 schrieb Mª José Sempere:
> We've created a table with a bytea type field.
> We'd like having no more than one row with identical content
> In that field. So, we've declared a unique index on that field.
> We'd like to know if in tables with a lot of rows the existence of that
> index will slow the insertion of new rows
Yes.
> (perhaps because before inserting
> it must compare that field with the content of the same bytea field
> For all the existing rows in the table).
Not with all rows, since it's a B-tree index, but with some rows for sure.
> We'd also like to know how does PostgreSql implement that comparation
> Between bytea fields (if it compares all the content of the field,
Yes.
--
Peter Eisentraut
http://developer.postgresql.org/~petere/