Shared Pool check – Every query possess a hash code during its execution. So, this check determines existence of written hash code in shared pool if code exists in shared pool then database will not take addit
{ "considered_execution_plans": [ { "plan_prefix": [ ], "table": "`user`", "best_access_path": { "considered_access_paths": [ { "access_type": "ref", "index": "idx_age", "rows": 1, "cost": 0.35, "chosen": true }, { "access_type": "range", "range_details": { "...
You can click on the 'Executed Plan' to go to the details of the execution. You can drill down in detail to see the execution steps. You Can see the filter conditions applied on the table. Figure 6: Executed Plan (showing filters details) You can click on the SQL button on the top...
ExecuteSQLExecutingQueryProvides information about the execution phases of the SQL statement. Log entries are written when the task acquires connection to the database, when the task starts to prepare the SQL statement, and after the execution of the SQL statement is completed. The log entry for...
ExecuteSQLExecutingQueryProvides information about the execution phases of the SQL statement. Log entries are written when the task acquires connection to the database, when the task starts to prepare the SQL statement, and after the execution of the SQL statement is completed. The log entry for...
ExecuteSQLExecutingQueryProvides information about the execution phases of the SQL statement. Log entries are written when the task acquires connection to the database, when the task starts to prepare the SQL statement, and after the execution of the SQL statement is completed. The log entry for...
The Oracle optimizer determines the most efficient execution plan and is the most important step in the processing of any SQL statement. The optimizer: • Evaluates expressions and conditions • Uses object and system statistics • Decides how to access the data ...
QEP_TAB是Query Execution Plan Table的缩写,这里的表Table对象主要包含物化表、临时表、派生表、常量表等。JOIN::optimize()是优化执行器的统一入口,在这里会把一个查询语句块Query_block最终优化成QEP_TAB。 在MySQL-8.0.22版本之后,又引入访问方式AccessPath和执行迭代器Iterator对象,再结合JOIN和QEP_TAB对象,最终...
Execution Steps: Step 1:Assesses if the source SQL Server instance is a member of an existing Always On Availability Group (AOAG) topology or if it is a standalone SQL Server instance. FCI instances are considered as standalone instance unless they participate in ...
Execution PlansTo run a DML statement, Oracle might need to perform many steps. Each of these steps either retrieves rows of data physically from the database or prepares them in some way for the user issuing the statement. The combination of the steps Oracle uses to run a statement is ...