Write latency – Shows the average amount of time in milliseconds taken for disk write I/O operations. You can evaluate the time for the write acknowledgment to return. When latency is high, it means that the sender spends more time idle (n…

Amazon Redshift でノード・スライスごとのブロック数を確認する。 select b.node, a.slice, sum(blocknum) from svv_diskusage a, stv_slices b where a.slice = b.slice group by b.node, a.slice order by b.node, a.slice, sum(blocknum) desc; node|sli…

Amazon Redshift の redistribute と broadcast の違いについてのメモ。 redistribute と broadcast(A copy of the entire table is broadcast to all the compute nodes) がある。 DS_DIST_OUTER The outer table is redistributed.DS_BCAST_INNER A copy o…