#1032 closed defect (fixed)

parallel query not working

Reported by: gmerticariu Owned by: gmerticariu
Priority: major Milestone:
Component: undecided Version: development
Keywords: Cc: pbaumann
Complexity: Medium

Description

if two retrieval (select) queries are executed, then the second one is waiting for the first one to finish.

e.g.

console 1: ./rasql -q 'select avg_cells(test - test/2 -test/3) from test' --out string

console 2: ./rasql -q 'select avg_cells(test - test/2 -test/3) from test' --out string

Result: Console 1 is executing, Console 2 is waiting -> Console 1 finishes, Console 2 is executing -> Console 2 finishes

Change History (7)

comment:1 Changed 17 months ago by dmisev

Hmm this shouldn't happen with select queries..

comment:2 Changed 17 months ago by dmisev

We have a bit of a problem with SQLite that is just becoming apparent -- SQLite is great for a multithreaded application, but not very optimal for our multiprocess environment.

I tend to think more and more that traditional PostgreSQL + filesystem for the tiles is the optimal backend for rasdaman.

comment:3 Changed 17 months ago by pbaumann

maybe related to the recent SQLite wait patch?

comment:4 Changed 17 months ago by pbaumann

maybe related to the recent SQLite patch?

comment:5 Changed 17 months ago by dmisev

Yes most likely, but I didn't expect it to affect purely select queries. It needs to be revised.

comment:6 Changed 17 months ago by dmisev

I submitted a patch, the issue was in starting IMMEDIATE transaction rather than regular one, which prevents other IMMEDIATE transactions to be started until it finishes.

comment:7 Changed 17 months ago by dmisev

  • Resolution set to fixed
  • Status changed from new to closed
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