I have 2 threads in my program can someone take a look at them and provide
some comments
Pseudo code for thread 1 (a is the primary key)
Thread1()
{
insert into tbl1(a,b,c,d,e,f,g,h,i,j,k);
}
So my pseudo code is(b and c have an index, a is primary key)
Thread2()
{
sleep(200);
prepare;
while(step)
{
Select a from tbl1 where b='yyy' c ='xxx' limit i offset (i + 1) ;
Update tbl1 set e=1 where a = some value from the select;
i = i + 1
}
}
If I run these 2 threads individually the tps is acceptable but if I run
them together the performance is woeful. I am running in serialized mode.
Both threads use different handles to DB. Please advice what I can do in
order to improve performance.
Another question - What kind of impact does a limit clause have? The columns
being used in the where clause are indexed. My current design is bad, I am
forced to use limit to get one row at a time. Since I have an index the
impact should be minimal. Please let me know if I am wrong.
cricketfan wrote:
>
> Hello I have a basic question and would be glad if someone can answer it.
> I understand that if we have "BEGIN TRANSACTION" and "END TRANSACTION"
> then the transaction(s) within that block would be committed, number of
> transactions could be 10,100,1000 or 10000..... . Otherwise, SQLITE by
> default commits for every single insert,update,delete.
> I have a prepare statement(using limit clause so will get only 10 rows
> back) followed by step(during which I use an update clause) so how would
> the transaction concept behave in this case? If I wrap the loop I use for
> stepping with a begin transaction(followed by an end transaction when the
> loop ends) would it be sufficient?
>
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