In the example below the table SALES does not have statistics, so the optimizer has used dynamic sampling during the query optimization, which is displayed in the plan using the +note' in the query: SELECT plan_table_output FROM TABLE(DBMS_XPLAN.DISPLAY('plan_table',null,'basic +note'))...
case T_NestLoop: case T_MergeJoin: case T_HashJoin: /* try not to be too chatty about this in text mode */ if (es->format != EXPLAIN_FORMAT_TEXT || (es->verbose && ((Join *) plan)->inner_unique)) ExplainPropertyBool("Inner Unique", ((Join *) plan)->inner_unique, es);...
In the execution plan, the first inner table usually has a Materialize operator. Optimization suggestion: The principle of nested loop is that the inner table is driven by the outer table. Each row returned by the outer table must match a row in the inner table. Therefore, the returned ...
EXPLAIN returnsa row of information for each table used in the SELECT statement. It lists thetables in the output in the order that MySQL would read them while processingthe statement. MySQL resolves all joins using a nested-loop join method. Thismeans that MySQL reads a row from the first ...
Each output row from EXPLAIN provides information about one table. Each row contains the values summarized in Table 10.1, “EXPLAIN Output Columns”, and described in more detail following the table. Column names are shown in the table's first column; the second column provides the equivalent pr...
Each output row from EXPLAIN provides information about one table. Each row contains the values summarized in Table 8.1, “EXPLAIN Output Columns”, and described in more detail following the table. Column names are shown in the table's first column; the second column provides the equivalent pro...
Oh my God. We used to have a song which was about all the things had to happen in the endgame, which is, "Oh no, Astarion's on fire, the Githyanki, you're leaving." And it was just all these things, they were like, "What sequence do they all happen in? Oh my God." ...
Actually, in the field of computer programming, there are many differences between algorithm and flowchart regarding various aspects, such as the accuracy, the way they display, and the way people feel about them. Below is a table illustrating the differences between them in detail. Algorithm ...
VERBOSE:Adds more detailed information about the execution plan. Example Usage of EXPLAIN in PostgreSQL Example 1: Basic EXPLAIN Usage Suppose you want to understand the execution plan for a simple SELECT query: Code: EXPLAIN SELECT * FROM orders WHERE customer_id = 123; ...
Tail recursion is just one of the many peculiar aspects of functional programming that, frankly, does not make that much different in the long run. (Frankly, a loop is about 20 times easier than tail recursion in about 90% of the cases; same for passing functions around). However, those...