/*
* The EXPLAIN for the SELECT query below shows the data for the authorized columns
* of the Lake Formation table. The row table filter is added
* as WHERE clause. The table row filter defined is
* ( price > 14999.99 ) OR ( ( mileage < 10000 ) OR ( make = 'Buick' ) )
* which is the combination of the three cell filters. See the REMOTE QUERY EXPLAIN for predicate
*/
explain select * from aws_lakeformation.otfdb.cardata_lf;
*** Help information returned. 30 rows.
*** Total elapsed time was 59 seconds.
Explanation
---------------------------------------------------------------------------
1) First, we do an all-AMPs RETRIEVE step executing table operator
TD_OTFDB.TD_ICEBERG_READ in TD_MAP1 with a condition of ("(1=1)").
The size of Spool 2 is estimated with no confidence to be 20,000
rows (427,200,000 bytes). The estimated time for this step is
0.00 seconds.
2) Next, we do an all-AMPs RETRIEVE step in TD_MAP1 from Spool 2
Last Use) by way of an all-rows scan executing table operator
TD_OTFDB.TD_ICEBERG_READ in TD_MAP1 with a condition of ("(1=1)")
nto Spool 4 (group_amps), which is built locally on the AMPs.
< BEGIN EXPLAIN FOR REMOTE QUERY -->
We connect to Iceberg GLUE catalog, then we retrieve and process 1
Row Filters Added to Existing Predicate
data files, with estimated row count of 804, that is about 9035
total bytes of row data from remote table otfdb.cardata_lf, for
the qualifying columns price,mileage,make, with push-down
predicate
([{"type":"LITERAL_PREDICATES","expression":{"type":"OR","left":{"type
":"GT","term":"price","value":14999.99},"right":{"type":"OR","left":{"
type":"LT","term":"mileage","value":10000},"right":{"type":"EQ","term"
:"make","value":"Buick"}}}},{"type":"FULL_PREDICATES","expression":{"t
type":"OR","left":{"type":"GT","term":"price","value":14999.99},"right"
:{"type":"OR","left":{"type":"LT","term":"mileage","value":10000},"rig
ht":{"type":"EQ","term":"make","value":"Buick"}}}}]).
<-- END EXPLAIN FOR REMOTE QUERY >
The size of Spool 4 is estimated with no confidence to be 20,000
rows (41,260,000 bytes). The estimated time for this step is 5.17
seconds.
3) Finally, we send out an END TRANSACTION step to all AMPs involved
in processing the request.
-> The contents of Spool 4, are sent back to the user as the result
of statement 1. The total estimated time is 5.17 seconds.
+---------+---------+---------+---------+---------+---------+---------+----