Concatenating field field oracle third two updating

Then two queries are issued, both specifying literal values in the 0 5 AND INSTR(sql_text, 'sql_text') = 0 6 ORDER BY sql_text; SQL_TEXT EXECUTIONS ------------------------------------------------------------ ---------- SELECT * FROM dual WHERE dummy = 'LITERAL1' 1 SELECT * FROM dual WHERE dummy = 'LITERAL2' 1 2 rows selected.

SQL From this we can see that both queries were parsed separately.

In a forum I frequent a question was raised regarding an index not being used.

The poster is using Oracle, which limits the index access paths Oracle can use; a concatenated index is created on the table (which has columns x,y,z,t,q and w, for lack of better names) on columns x, y, and z.

Of course having no data in the table means that even if you do generate statistics they will be essentially useless.

Let's set this up with, using a single-column index (since at the time this example was created the existence of the concatenated index wasn't known) and see what happens: begin 2 for i in 1..100000 loop 3 insert into emp2 4 select * from emp; 5 6 update emp2 7 set empno = empno i, mgr=mgr i, updated='YES' 8 where updated is null; 9 10 commit; 11 end loop; 12 13 commit; 14 end; 15 / PL/SQL procedure successfully completed.

If the statement is found in the shared pool this step is not necessary and a soft parse is performed.function requires at least two arguments (which can be the empty sequence), and accepts an unlimited number of additional arguments.This is the only XQuery XPath 2.0 function that has a flexible number of arguments, for compatibility with XPath 1.0. The function does not accept a sequence of values, just individual atomic values passed as separate arguments.Substitution variables are a feature of the SQL*Plus tool.They have nothing to do with the way SQL is processed by the database server.

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