after `Query execution was interrupted` can not access table

Question

I was running a simple query in MySQL, joining two tables and getting where it doesn't match. Both tables have 500k data. my query was something like

select count(*) from t1 join t2 t1.id <> t2.id

and after 300 seconds I got following error

Error Code: 1317. Query execution was interrupted

after that, I could not run a simple query on that table, like

select * from t1 limit 50

but all other tables were working and my system also got down for a while. Finally, I restarted my MySQL server then everything started working.

Any idea why my table got stuck??

TIA

I think that means you are joining each row in T1 with ALL BUT ONE row in T2. Making a HUGEMUNGOUS set of data — RiggsFolly
– RiggsFolly, Commented Jun 9, 2020 at 15:05
I was trying to get unmatched data from the table. I understand that because of my query execution was interrupted. But why my table got locked? — ANIK ISLAM SHOJIB
– ANIK ISLAM SHOJIB, Commented Jun 9, 2020 at 15:33
ok, I understand that my table got locked and I have to unlock the table, but I have encountered that error multiple times but the table never got locked. May be expensive query caused that. Thanks for your co-operation. — ANIK ISLAM SHOJIB
– ANIK ISLAM SHOJIB, Commented Jun 9, 2020 at 15:38
Really depends upon what the query was doing when the crash occured as to whether is will crash a table or not — RiggsFolly
– RiggsFolly, Commented Jun 9, 2020 at 15:39

Jonathan Delean · Accepted Answer · 2020-06-09 15:16:32Z

2

Your table was locked, if a query crash for some reason, you have to kill your query to unlock you table (or restart your mysql server)

answered Jun 9, 2020 at 15:16

Jonathan Delean

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