Instead, we use the binary MySQL encoding and copy the data directly
into the QVariant of the desired type. This gets rid of the temporary
string allocations and greatly improves the performance of the added
benchmark. On my machine, the results are:
Before:
0.562 msecs per iteration (total: 563, iterations: 1000)
1,922,479.330 instructions per iteration (total: 1,922,479,330, iterations: 1000)
After:
0.381 msecs per iteration (total: 381, iterations: 1000)
774,132.957 instructions per iteration (total: 774,132,958, iterations: 1000)
Note that the same could be applied to floating point data types in
the future. Additionally, special support for MYSQL_TIME structure
coult be added to get rid of the string conversions there.
To ensure everything keeps working, a new auto test is added as well
that verifies the select statements and insertions of integral data
into a MySql table works as intended.
[ChangeLog][QtSql] Improve performance when reading integer values
from MySQL databases via prepared statements.
Change-Id: I21dd9277661971ded934546f09535014b63f8eb8
Reviewed-by: Olivier Goffart (Woboq GmbH) <ogoffart@woboq.com>
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|---|---|---|
| .. | ||
| auto | ||
| baselineserver | ||
| benchmarks | ||
| global | ||
| manual | ||
| shared | ||
| README | ||
| tests.pro | ||
README
This directory contains autotests and benchmarks based on Qt Test. In order
to run the autotests reliably, you need to configure a desktop to match the
test environment that these tests are written for.
Linux X11:
* The user must be logged in to an active desktop; you can't run the
autotests without a valid DISPLAY that allows X11 connections.
* The tests are run against a KDE3 or KDE4 desktop.
* Window manager uses "click to focus", and not "focus follows mouse". Many
tests move the mouse cursor around and expect this to not affect focus
and activation.
* Disable "click to activate", i.e., when a window is opened, the window
manager should automatically activate it (give it input focus) and not
wait for the user to click the window.