Re: Co-located Joins & Data Locality in HAWQ

2016-09-22 Thread Hubert Zhang
Randomly distributed tables make Hawq2.x more elastic: big queries use more resources, while small queries will use less resources. But hash distributed table need to use the same number of resource as the bucket number of table, no matter the query cost is large or small. As a result, a scan on a

Co-located Joins & Data Locality in HAWQ

2016-09-20 Thread Vineet Goel
Hi all, I have received a fair number of questions on the topic of handling data locality and co-located joins in HAWQ 2. Most of the questions are coming from the background where HAWQ 1.x defaulted to HASH distributed tables distributed by a key and hence resulted in local joins in most cases fo