|
You are here |
sqlmaria.com | ||
| | | | |
hourim.wordpress.com
|
|
| | | | | The last Jonathan Lewis post on RAC Planswhich finished by the following phrases: "If you're going to hard-code hints into a query then take a look at the outline it generates when it does the right thing, and that will tell you about the 15 or so hints you've missed out. (Better still, consider generating... | |
| | | | |
jonathanlewis.wordpress.com
|
|
| | | | | Jump to summary. A new optimizer feature that appears in 23c (probably not 21c) was the ability to push group by clauses into union all set operations. This will happen unhinted, but can be hinted with the highly memorable [no_]push_gby_into_union_all() hint that appeared in 23.1.0.0 according to v$sql_hint. and the feature can be disabled by... | |
| | | | |
dioncho.wordpress.com
|
|
| | | | | One of my colleagues sent following test case, of which he couldn't control the join order with hints. 1. Create objects - table t1, t2 and t3 2. Now Let's set the join order as T1->T2->T3, using global hints convention. But it seems that Oracle does not work as expected. It really seems that the... | |
| | | | |
tanelpoder.com
|
|
| | | Update: As this original article is from 2007, there are better options available in the modern times for example DBMS_UTILITY.EXPAND_SQL_TEXT as explained by Maria Colgans blog entry here. If you have been involved in tuning SQL code which you have never seen before, you are probably familiar with the challenges of understanding what the code is trying to do. This can be especially time consuming when the SQL references lots of views, which reference views, which reference more views etc. So there may ... | ||