Alexander, If they do this at the moment
> If they issue "explain > update...", there's no problem to return output for EXPLAIN SELECT > without requiring anything else from the user. then they will get an exception. My question was what are the efforts to support this? — Denis > On Dec 26, 2016, at 2:05 AM, Alexander Paschenko > <alexander.a.pasche...@gmail.com> wrote: > > Users won't need to create that query. If they issue "explain > update...", there's no problem to return output for EXPLAIN SELECT > without requiring anything else from the user. > > From EXPLAIN, the user usually expects to find out which indexes will > be used by their query. And that's what EXPLAIN for SELECT gives. > > - Alex > > 2016-12-23 21:36 GMT+03:00 Denis Magda <dma...@apache.org>: >> This might be a tricky part for the users because they need to recreate the >> query manually >> >>> UPDATE Person SET name = 'John' WHERE surname = 'Smith', >>> >>> then we could show >>> >>> EXPLAIN SELECT _key from Person WHERE surname = 'Smith’; >> >> How difficult is to support EXPLAIN for DML in general? Let’s discuss the >> challenges and implementation details and create a ticket after that. >> >> — >> Denis >> >> >>> On Dec 23, 2016, at 7:46 AM, Alexander Paschenko >>> <alexander.a.pasche...@gmail.com> wrote: >>> >>> Denis, >>> >>> Currently there's no API to get those queries. However, they are >>> always generated under the hood - except for 'fast' UPDATE and DELETE >>> that don't need any queries. >>> So what is suggested in docs is to EXPLAIN those SELECTs - say, if we >>> have DML statement >>> >>> UPDATE Person SET name = 'John' WHERE surname = 'Smith', >>> >>> then we could show >>> >>> EXPLAIN SELECT _key from Person WHERE surname = 'Smith'; >>> >>> - Alex >>> >>> 2016-12-23 3:09 GMT+03:00 Denis Magda <dma...@apache.org>: >>>> Alex P., Sergi, >>>> >>>> All we know that EXPLAIN is not supported for DML statements at the moment. >>>> http://apacheignite.gridgain.org/docs/dml#section-explain-support-for-dml-statements >>>> >>>> However, I can’t get how I can get over this limitation for UPDATE and >>>> DELETE statements following this recommendation >>>> >>>> "One possible approach is to execute EXPLAIN for the SELECT automatically >>>> generated (UPDATE, DELETE) or used (INSERT, MERGE) by DML statements. This >>>> will give an insight on the indexes that are used while a DML operation is >>>> executed.” >>>> >>>> How can I get SELECT queries that are generated by these DML operations >>>> automatically? >>>> >>>> — >>>> Denis >>
