Large intermediate results dureing columns update
gms_xy at gmx.de
Fri Oct 17 11:40:54 CEST 2014
Given a column defined as bigint (int64) with 1 billion rows. Storage size of this column is 8 GB. Values range in space of int (int32).
vkont_int32 = vkont_int64
This query takes very long (minutes). During execution the data directory grows by 40 GB (!). I would expect the data cells do be converted an written into the new column directly. Even if MonetDB would materialize the whole source column as "intermediate result", I would expect not to exceed 8 GB for "intermediates" and 4 GB for the target column.
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