This Qt project shows an implementation of custom filtering in large tables (4 columns, 250000 rows). Each column has its own QLineEdit. Optionally you can set QCheckBox if you want to filter for Qt::CheckState.

• Load FilterHeader.pro in your Qt Creator and select Qt5 kit
• Run

If you need Qt4 support, replace setSectionsClickable() with setClickable() and setSectionsMovable() with setMovable() in filterheader.cpp.

Adjust rowCount or columnCount to your needs.

Try playing around with filterReactionTime if your table is even larger or you have a strong machine.