projection on tables having leftouter join in vertica 7.1.1

Chirag_1

Hi,
I am new in Vertica. We are using vertica7.1.1. I have query having 10 leftouter joins. How I can create projection on it to improve performance.Any example will be helpful. Is there any alternative to improve performance of query

id10t

Hi!

Without a query requirements and query itself no one can help you. Vertica isn't a "magic black box", you need to be more concrete.

• What query should do?
  
• Can we rewrite it in other form with less joins?
• May be some analytical functions can reduce a joins amount?
• May be a custom UDF will be a best solution here?(for recursions and regressions)

Regards.

Prasanta_Pal

The comment from id-10-t is definitely true:


For some example on left outer or right outer in vertica, review the below link.

In general, the projections for fact tables should be segmented while for the dimension tables they should be always replicated. Based on the data, vertica will determine which one would be the inner and which one should be outer tables.

http://my.vertica.com/docs/7.1.x/HTML/index.htm#Authoring/AnalyzingData/Queries/OuterJoins.htm?Highl...