Hello,
I am currently working on a project related to query optimization I have several questions, 1) Is it possible to force the query engine to use the specified join order? 2) When I change the table order in the “FROM” clause, the query time varies a lot (many orders of magnitude)? Does the table order in the “FROM” clause affect the query plan? 3) I want to know the details of MonetDB query plan. When I use “explain” command, I just get the MAL code. Are there any tools to visualize it, just like PostgreSQL “analyze" command?
Thanks a lot.
Hi,
since you seem to be in a hurry (or just impatient?), here some quick answers:
1) No. 2) Apparently. 3) Please check whether any of these help you further: https://www.monetdb.org/Documentation/Manuals/SQLreference/Runtime https://www.monetdb.org/Documentation/Cookbooks/SQLrecipes/QueryTiming
Best, Stefan
----- On Sep 7, 2018, at 8:59 PM, Junxiong Wang chuangzhetianxia@gmail.com wrote:
Hello,
I am currently working on a project related to query optimization I have several questions, 1) Is it possible to force the query engine to use the specified join order? 2) When I change the table order in the “FROM” clause, the query time varies a lot (many orders of magnitude)? Does the table order in the “FROM” clause affect the query plan? 3) I want to know the details of MonetDB query plan. When I use “explain” command, I just get the MAL code. Are there any tools to visualize it, just like PostgreSQL “analyze" command?
Thanks a lot.
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participants (2)
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Junxiong Wang -
Stefan Manegold