sqlite3 speed performances

LYD29 · wrote on 20 Jan 2016, 14:26

Hi all,

I'm a relatively beginner in Qt development and I'm working on a Qt app which uses sqlite3 to read and write a sqlite database.
Currently, I'm trying to improve the speed of the requests' executions. Indeed, some of them take a too long time to process.

For example : the request "SELECT * FROM TABLE1 ORDER BY DATES DESC;" takes 1.662s to be executed by Sqliteman app while it takes 21.9s to be executed by my Qt app.
When I add an index to this DATES column, the speed is increased via Sqliteman app (0.056s) while my Qt app takes again more than 22s.

I don't know which information you can need to understand my problem. So, please ask me if necessary.

Thanks in advance for helping me !

SGaist · wrote on 20 Jan 2016, 22:37

Hi,

Which size is that table ?

How are you setting things up ?

LYD29 · wrote on 21 Jan 2016, 07:21

Hi,

The table contains almost 189000 lines and 7 columns. Nevertheless, the number of lines grows with the functioning of my machine. This machine measures some parameters frequently and add lines in this table to memorize measurements' values.
It's one of my predecessors who created this database and wrote the code to read and write. So I don't know how to improve it.

My Qt code is compiled for arm. I use the sqlite3 library (sqlite3.h and sqlite3.c are in the sources).

Thanks

SGaist · wrote on 21 Jan 2016, 21:18

How are you querying the database with Qt ?