Snowflake joins performance improvement - join

Question

I need to create a view on top of a table which contains 1300+ columns. New data will be loaded to table every quarter(Rows in millions). While creating view I need to join other table with the base table. and i also needed to add a recent row indicator in view.
CREATE OR REPLACE SECURE VIEW VIEW_NAME AS
SELECT lkp_tbl.col1,base_tbl.col1,base_tbl.col2,base_tbl.col3,........,
base_tbl.col1334, 1 as Is_Latest_Quarter
FROM base_tbl full outer JOIN lkp_tbl
on base_tbl.CUST_ID = lkp_tbl.CUST_ID
where snapshot_dt=(select max(snapshot_dt) from base_tbl)
union all
SELECT lkp_tbl.col1,base_tbl.col1,base_tbl.col2,base_tbl.col3,........,
base_tbl.col1334,0 as Is_Latest_Quarter
FROM base_tbl full outer JOIN lkp_tbl
on base_tbl.CUST_ID = lkp_tbl.CUST_ID
where snapshot_dt!=(select max(snapshot_dt) from base_tbl);
After creating this view the performance of the query is too slow even if we are querying 100 rows. Is there a way in which we can create view in more efficient way. If not how can i increase performance?

Answer 1

just use one SELECT statement and use a CASE statement to calculate Is_Latest_Quarter
UPDATED WITH (ALMOST) ACTUAL SQL
CREATE OR REPLACE SECURE VIEW VIEW_NAME AS
SELECT {list of columns you want to include}
,CASE WHEN snapshot_dt=(select max(snapshot_dt) from base_tbl) THEN 1
ELSE 0 END as Is_Latest_Quarter
FROM base_tbl
full outer JOIN lkp_tbl on base_tbl.CUST_ID = lkp_tbl.CUST_ID
Alternatively, if Snowflake doesn't like that in-line subquery, your could use a CTE something like:
CREATE OR REPLACE SECURE VIEW VIEW_NAME AS
WITH MAX_DATE AS (SELECT MAX(Ssnapshot_dt) AS max_snapshot_dt FROM base_tbl),
SELECT {list of columns you want to include}
,CASE WHEN max_date.max_snapshot_dt is not null THEN 1
ELSE 0 END as Is_Latest_Quarter
FROM base_tbl
full outer JOIN lkp_tbl on base_tbl.CUST_ID = lkp_tbl.CUST_ID
LEFT OUTER JOIN MAX_DATE ON base_tbl.snapshot_dt = max_date.max_snapshot_dt