Query OK, 0 rows affected (0,00 sec) The only output we now get from this EXPLAIN is a "Query OK". If we want to see the full EXPLAIN output we couldSELECT @explain_output;, but the full JSON output takes so much space, and I'm only interested in the cost. To extract the cos...
loop inner join (cost=2.86 rows=4) (actual time=0.039,0.039,0.039..0.039,0.039,0.039 rows=0,0,0 loops=1,1,1) -> Nested loop inner join (cost=1.45 rows=1) (actual time=0.037,0.037,0.037..0.037,0.037,0.037 rows=0,0,0 loops=1,1,1) -> Parallel table scan on customer, with par...
JOINS: Amazon Redshift uses different join operators based on the physical design of the tables being joined, the location of the data required for the join, and specific attributes of the query itself. Subquery Scan -- Subquery scan and append are used to run UNION queries. Nested Loop n...
For example, if a hash aggregate operator is used in the first step of a query plan, full data of downstream operators is required to create a hash table for an aggregate operation. For common queries with filter conditions, data is calculated and returned in real time. In this scenario, ...
Query Plan --- SELECT STATEMENT [CHOOSE] Cost=1 FILTER *** This is like a bounded nested loops TABLE ACCESS FULL EMP [ANALYZED] FILTER *** This filter is introduced by the min SORT GROUP BY NOSORT INDEX FULL SCAN BE_IX This example is also interesting...
The EXPLAIN command provides information about how MySQL executes queries. EXPLAIN can work with SELECT, DELETE, INSERT, REPLACE, and UPDATE statements. We'll first analyze the original query, then attempt to optimize the query and look into the optimiz
(cost=103382.56 rows=1029632) -> Nested loop inner join (cost=409.36 rows=4022) -> Filter: (nation.N_NAME = 'IRAN') (cost=2.29 rows=3) -> Table scan on nation (cost=2.29 rows=25) -> Parallel index lookup on supplier using SUPPLIER_FK1 (S_NATIONKEY=nation.N_NATIONKEY), with ...
CREATEINDEXidx_value_3ONkvstore(valueASC)INCLUDE(key); If you run the same query, you should see the following output: 1# EXPLAIN (ANALYZE, DIST, COSTS OFF) SELECT * FROM kvstore WHERE value LIKE 'ca%' ORDER BY VALUE;2QUERY PLAN3---4Index Only Scan using idx_value_3 on kvstore (a...
All the operators in the query plan are nested inside subQuery1 that is referenced by DFESubquery. All the operators that are pushed down to the DFE engine have names that start with a DFE prefix. As mentioned above, the whole openCypher query plan is executed by the DFE, so as a ...
Explain output is limited by the maximum Nested Depth for BSON Documents, which is 100 levels of nesting. Explain output that exceeds the limit is truncated. For details on the output, see Explain Results. Examples queryPlanner Mode By default, db.collection.explain() runs in "queryPlanner...