* in *es are initialized here. * * NB: will not work on utility statements */voidExplainPrintPlan(ExplainState *es, QueryDesc *queryDesc){ Bitmapset *rels_used = NULL; PlanState *ps; /* Set up ExplainState fields associated with this plan tree */ Assert(queryDesc->plannedstmt != ...
the MySQL optimizer considers many techniques to efficiently performthe lookups involved in an SQL query. A query on a huge table can be performedwithout reading all the rows; a join involving several tables can be performedwithout comparing every combination of rows. The set of operations...
You cannot usethe EXTENDED and PARTITIONS keywords together in the same EXPLAIN statement. In addition, neither of these keywordscan be used together with the FORMAT option. (FORMAT=JSON causesEXPLAIN to display extended and partition informationautomatically; using FORMAT=TRADITIONAL has no effect on ...
The value of this parameter is in the format of maximum memory resource consumption/average memory resource consumption/minimum memory resource consumption. Example: mem=3528/1172/584B. An SQL statement may involve multiple operators. For more information about operators, see Operators. Note When...
EXPLAIN operatorsQuery execution stepsDescription SCAN: Sequential ScanscanAmazon Redshift relation scan or table scan operator or step. Scans whole table sequentially from beginning to end; also evaluates query constraints for every row (Filter) if specified with WHERE clause. Also used to run INSERT...
For example, J3_1_2_Stg1 indicates that the task with the ID of 3 depends on the M1 and M2 tasks. Dependencies between all operators in a task The operator string describes the execution semantics of a task. Operator string structure: In Task M2: Data source: mf_mc_bj.sale_detail...
(*))]) 1 - output([T_FUN_COUNT(*)]), filter(nil), rowset=256 access(nil), partitions(p0) is_index_back=false, is_global_index=false, range_key([t1.__pk_increment]), range(MIN ; MAX)always true 1 row in set Explain an SQL query to obtain its execution plan without ...
1 BEST PRACTICES FOR GATHERING OPTIMIZER STATISTICS WITH ORACLE DATABASE 18C The Execution Plan An execution plan shows the detailed steps necessary to execute a SQL statement. These steps are expressed as a set of database operators that consume and produce rows. The order of the operators and...
For more information about how to use this format, see SQL Plan Management. plan_cache The EXPLAIN statement outputs results in the row format, with the Plan Cache information as a warning. brief DotGraph JSON The following is an example when FORMAT is "brief" in EXPLAIN: EXPLAIN FORMAT =...
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