Re: [sqlite] group_concat optimization

2009-10-15 Thread Olaf Schmidt
"Pavel Ivanov" schrieb im Newsbeitrag news:f3d9d2130910150647k5e28d8aan81d60fad8e71e...@mail.gmail.com... > > Would the authors be kind to implement such optimization? > > I'm not author but I believe the answer to this question is No. > Because this fix is good enough for you but may be not good

Re: [sqlite] group_concat optimization

2009-10-15 Thread Pavel Ivanov
> Would the authors be kind to implement such optimization? I'm not author but I believe the answer to this question is No. Because this fix is good enough for you but may be not good for others. Your fix gets more memory than is really needed and it can be a problem for embedded devices. But you'

[sqlite] group_concat optimization

2009-10-14 Thread ??????? ????????
I make use of group_concat aggregate function and I found it very slow, especially when there are thousands of lines per group. This is because it reallocates memory on each processed row. I changed just one line in sqlite3StrAccumAppend(): szNew += N + 1 to something like this: do{ szNe